Network Management

This book is a part of the course by Jaipur National University, Jaipur.This book contains the course content for Network Management.

JNU, JaipurFirst Edition 2013

The content in the book is copyright of JNU. All rights reserved.No part of the content may in any form or by any electronic, mechanical, photocopying, recording, or any other means be reproduced, stored in a retrieval system or be broadcast or transmitted without the prior permission of the publisher.

JNU makes reasonable endeavours to ensure content is current and accurate. JNU reserves the right to alter the content whenever the need arises, and to vary it at any time without prior notice.

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Index

ContentI. ...................................................................... II

List of FiguresII. ..........................................................VI

List of TablesIII. ......................................................... VII

AbbreviationsIV. ......................................................VIII

Case StudyV. ................................................................ 95

BibliographyVI. ........................................................... 99

Self Assessment AnswersVII. ................................... 101

Book at a Glance

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Content

Chapter I ....................................................................................................................................................... 1Data Communication and Network Management Overview ................................................................... 1Aim ................................................................................................................................................................ 1Objectives ..................................................................................................................................................... 1Learning outcome .......................................................................................................................................... 11.1 Introduction ............................................................................................................................................. 21.2 Data Communication ............................................................................................................................... 21.3 Analogy of Telephone Network Management ......................................................................................... 21.4 Communication Protocols and Standards ............................................................................................... 31.5 Network Management: Goals, Organisation and Functions .................................................................... 41.6 Goal of Network Management ................................................................................................................. 4 1.6.1 Network Provisioning .............................................................................................................. 5 1.6.2 Network Operations and NOC ................................................................................................. 6 1.6.3 Network Installation and Maintenance .................................................................................... 61.7 Challenges on Information Technology Managers .................................................................................. 61.8 Current Trends in Network Management ................................................................................................ 7Summary ...................................................................................................................................................... 8References .................................................................................................................................................... 8Recommended Reading ............................................................................................................................... 8Self Assessment ............................................................................................................................................ 9

Chapter II ....................................................................................................................................................11SNMPV Network Management .................................................................................................................11Aim ...............................................................................................................................................................11Objectives ....................................................................................................................................................11Learning outcome .........................................................................................................................................112.1 Introduction ............................................................................................................................................ 122.2 SNMP History ........................................................................................................................................ 122.3 SNMP Model Network .......................................................................................................................... 12 2.3.1 SNMP Requests ..................................................................................................................... 13 2.3.2 Monitoring of Network .......................................................................................................... 142.4 Versions of SNMP .................................................................................................................................. 14 2.4.1 SNMPv1 ................................................................................................................................. 14 2.4.2 SNMPv2 ................................................................................................................................. 15 2.4.3 SNMPv3 - The Security Extension ........................................................................................ 162.5 Threats in Network Security .................................................................................................................. 17 2.5.1 Masquerading ......................................................................................................................... 17 2.5.2 Changes of Information ......................................................................................................... 17 2.5.3 Changes in Message Stream ................................................................................................. 17 2.5.4 Disclosure .............................................................................................................................. 17 2.5.5 Block of Service ..................................................................................................................... 17 2.5.6 Ignorance of Message ............................................................................................................ 182.6 Information Model ................................................................................................................................. 18 2.6.1 Three Tiered Model of Information ....................................................................................... 18Summary .................................................................................................................................................... 20References ................................................................................................................................................... 20Recommended Reading ............................................................................................................................. 20Self Assessment .......................................................................................................................................... 21

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Chapter III .................................................................................................................................................. 23Remote Monitoring ................................................................................................................................... 23Aim .............................................................................................................................................................. 23Objectives ................................................................................................................................................... 23Learning outcome ........................................................................................................................................ 233.1 Remote Monitoring ................................................................................................................................ 243.2 RMON Groups ....................................................................................................................................... 243.3 ATM Remote Monitoring ...................................................................................................................... 25Summary ..................................................................................................................................................... 27References ................................................................................................................................................... 27Recommended Reading ............................................................................................................................. 27Self Assessment .......................................................................................................................................... 28

Chapter IV .................................................................................................................................................. 30Telecom Management Network ............................................................................................................... 30Aim .............................................................................................................................................................. 30Objectives ................................................................................................................................................... 30Learning outcome ........................................................................................................................................ 304.1 Telecom Management Network ............................................................................................................. 314.2 TMN Standard........................................................................................................................................ 31 4.2.1 TMN, OSI and Management.................................................................................................. 32 4.2.2 TMN Solutions....................................................................................................................... 324.3 The TMN Functional Model .................................................................................................................. 324.4 OSI Function in TMN ............................................................................................................................ 33 4.4.1 Q Interface ............................................................................................................................. 344.5 TMN Logical Model .............................................................................................................................. 35Summary ..................................................................................................................................................... 36References ................................................................................................................................................... 36Recommended Reading ............................................................................................................................. 36Self Assessment .......................................................................................................................................... 37

Chapter V .................................................................................................................................................... 39Network Management Tools and Systems ............................................................................................... 39Aim .............................................................................................................................................................. 39Objectives ................................................................................................................................................... 39Learning outcome ........................................................................................................................................ 395.1 Network Management Tools .................................................................................................................. 405.2 Social Network Analysis ........................................................................................................................ 405.3 SNA as a Diagnostic Tool ..................................................................................................................... 415.4 System Management ............................................................................................................................. 41 5.4.1 System Management Lifecycle ............................................................................................. 415.5 System Management Task ..................................................................................................................... 425.6 Solutions for System Management Task ................................................................................................ 44 5.6.1 Apple Remote Desktop 3 ....................................................................................................... 44 5.6.2 Mac OS X Server ................................................................................................................... 455.7 Enterprise Management System ............................................................................................................ 455.8 Network Architecture ............................................................................................................................ 465.9 Commercial Network Management System .......................................................................................... 47Summary ..................................................................................................................................................... 48References ................................................................................................................................................... 48Recommended Reading ............................................................................................................................. 48Self Assessment ........................................................................................................................................... 49

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Chapter VI .................................................................................................................................................. 51Universal Mobile Telecommunications System ....................................................................................... 51Aim .............................................................................................................................................................. 51Objectives .................................................................................................................................................... 51Learning outcome ........................................................................................................................................ 516.1 Introduction ............................................................................................................................................ 526.2 UMTS Basics ......................................................................................................................................... 526.3 UMTS Services ...................................................................................................................................... 536.4 UMTS System Architecture ................................................................................................................... 536.5 Migration Path of UMTS ....................................................................................................................... 546.6 UMTS Spectrum Allocation .................................................................................................................. 546.7 The UMTS Air Interface ........................................................................................................................ 55 6.7.1 WCDMA Basics..................................................................................................................... 55 6.7.1.1 Calculating Spreading Factor .................................................................................. 56 6.7.2 The WCDMA Air Interface ................................................................................................... 57 6.7.2.1 Uplink Spreading, Scrambling and Modulation ...................................................... 58 6.7.2.2 Downlink Spreading, Scrambling and Modulation ................................................. 59 6.7.3 WCDMA Air-Interface Protocol Architecture ....................................................................... 60 6.7.4 WCDMA Channel Types ....................................................................................................... 61 6.7.4.1 Logical Channels ..................................................................................................... 61 6.7.4.2 Transport Channels .................................................................................................. 62 6.7.4.3 Physical Channels ................................................................................................... 646.8 Power Control in WCDMA ................................................................................................................... 70 6.8.1 Uplink Power Control ............................................................................................................ 70 6.8.2 Downlink Power Control ....................................................................................................... 706.9 Multi-rate User Data Transfer ................................................................................................................ 71 6.9.1 Channel Coding ..................................................................................................................... 71 6.9.2 Convolutional Coding ............................................................................................................ 72 6.9.3 Turbo Coding ......................................................................................................................... 72 6.9.3.1 Error Detection ........................................................................................................ 72 6.9.3.2 Error Correction ...................................................................................................... 726.10 Establishment of UMTS Speech Call .................................................................................................. 736.11 UMTS Packet Data (R99) .................................................................................................................... 76 6.11.1 GSM and UMTS Packet Data .............................................................................................. 76 6.11.1.1 GPRS Elements ..................................................................................................... 76 6.11.1.2 UMTS Elements .................................................................................................... 77 6.11.2 GPRS and UMTS PS Domain System Architecture ............................................................ 77 6.11.3 GPRS and UMTS PS Domain Service Capabilities ............................................................ 79 6.11.4 GPRS and UMTS PS Domain Terminal .............................................................................. 80Summary ..................................................................................................................................................... 82References ................................................................................................................................................... 82Recommended Reading ............................................................................................................................. 82Self Assessment ........................................................................................................................................... 83

Chapter VII ................................................................................................................................................ 85Web Based Management and Web Based Element ................................................................................ 85Aim .............................................................................................................................................................. 85Objectives .................................................................................................................................................... 85Learning outcome ........................................................................................................................................ 857.1 Web Based Management ........................................................................................................................ 867.2 Embedded Web Based Management ...................................................................................................... 867.3 Web based Network Management ........................................................................................................ 867.4 Web Based Enterprise Management ...................................................................................................... 877.5 Java Management Extension .................................................................................................................. 88 7.5.1 Instrumentation Level ............................................................................................................ 89

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7.5.2 Agent Level ............................................................................................................................ 89 7.5.3 Distributed Service Level ...................................................................................................... 897.6 Storage Area Network ............................................................................................................................ 90 7.6.1 SAN Management Software .................................................................................................. 90 7.6.2 Road Ahead ............................................................................................................................ 91Summary ..................................................................................................................................................... 92References .................................................................................................................................................. 92Recommended Reading ............................................................................................................................. 92Self Assessment ........................................................................................................................................... 93

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List of Figures

Fig. 1.1 Block diagram of communication system ........................................................................................ 2Fig. 1.2 Telephone model network ................................................................................................................. 3Fig. 1.3 Network management functional groupings ..................................................................................... 5Fig. 1.4 Network management and functional flow chart ............................................................................. 6Fig. 2.1 SNMP concept ................................................................................................................................ 13Fig. 2.2 Three tier model of information ..................................................................................................... 19Fig. 3.1 RMON probe .................................................................................................................................. 24Fig. 3.2 ATM remote monitoring ................................................................................................................. 26Fig. 4.1 Connections between TMN ............................................................................................................ 31Fig. 4.2 TMN building blocks ...................................................................................................................... 32Fig. 4.3 Standard interface between TMN components............................................................................... 34Fig. 4.4 Q interfaces ..................................................................................................................................... 34Fig. 4.5 TMN logical model......................................................................................................................... 35Fig. 5.1 System management life cycle ....................................................................................................... 42Fig. 5.2 System management task ................................................................................................................ 43Fig. 5.3 (a) Centralised network architecture ............................................................................................... 46Fig. 5.3 (b) Hierarchical network architecture ............................................................................................. 46Fig. 5.3 (c) Distributed network architecture ............................................................................................... 47Fig. 6.1 UMTS system architecture ............................................................................................................. 54Fig. 6.2 DS-CDMA basic concept ............................................................................................................... 56Fig. 6.3 Frequency utilisation with WCDMA .............................................................................................. 58Fig. 6.4 Uplink spreading, scrambling and modulation ............................................................................... 59Fig. 6.5 Downlink spreading, scrambling and modulation .......................................................................... 60Fig. 6.6 Air interface protocol architecture .................................................................................................. 60Fig. 6.7 Logical channel structure ................................................................................................................ 61Fig. 6.8 Mapping between logical and transport channels ........................................................................... 64Fig. 6.9 Frame structure for uplink DPDCH/DPCCH ................................................................................. 65Fig. 6.10 RACH access slot numbers and their spacing .............................................................................. 66Fig. 6.11 Structure of the random-access transmission ............................................................................... 66Fig. 6.12 Structure of the random-access message part radio frame ........................................................... 67Fig. 6.13 Structure of the CPCH random-access transmission .................................................................... 67Fig. 6.14 Frame structure for downlink DPCH ............................................................................................ 67Fig. 6.15 Frame structure for primary CCPCH ............................................................................................ 68Fig. 6.16 Frame structure for secondary CCPCH ........................................................................................ 69Fig. 6.17 Structure of synchronisation channel ........................................................................................... 69Fig. 6.18 Frame structure for the PDSCH .................................................................................................... 70Fig. 6.19 Establishing a speech call in UMTS ............................................................................................. 75Fig. 6.20 GPRS architecture ........................................................................................................................ 76Fig. 6.21 3GPP UMTS architecture ............................................................................................................. 77Fig. 6.22 The GPRS user plane and control plane ....................................................................................... 78Fig. 7.1 Web based element architecture ..................................................................................................... 86Fig. 7.2 Web based network management architecture................................................................................ 87Fig. 7.3 Structure of WBEM elements ......................................................................................................... 88Fig. 7.4 JMX architecture ............................................................................................................................ 89Fig. 7.5 Storage Area Network (SAN) ......................................................................................................... 90Fig. 7.6 Future of SAN ................................................................................................................................ 91

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List of Tables

Table 3.1 RMON monitoring group ............................................................................................................. 25Table 4.1 System components ...................................................................................................................... 33Table 4.2 TMN interfaces ............................................................................................................................ 33Table 6.1 Spreading factors and the corresponding data rates on the uplink ............................................... 56Table 6.2 Downlink spreading factors and data rates .................................................................................. 57Table 6.3 Logical control channels .............................................................................................................. 62Table 6.4 Traffic channels ............................................................................................................................ 62Table 6.5 Common transport channels ......................................................................................................... 63Table 6.6 Primary and secondary CPICH .................................................................................................... 68Table 6.7 Error correction coding parameters .............................................................................................. 72

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Abbreviations

ADSL – Asymmetric Digital Subscriber LoopASN – Abstract Syntax Notation OneATM – Automated Transaction MachineBoS – Block of ServiceCIM – Common Information ModelCIMOM – CIM Object ManagerCIO – Chief Information OfficerCMIP – Common Management Information ProtocolCRM – Customer Relations ManagementDAS – Direct Attached StorageEWS – Embedded Web ServerFPGA – Field-programmable Gate ArrayGDMO – Guideline for Definition of Managed ObjectJMX – Java Management ExtensionMCF – Message Communication FunctionMIB – Management Information BaseMOF – Managed Object FormatNAT – Network Address TranslationNOC – Network OperationNSS – Network and Switching SubsystemOAMP – Operation, Administration, Maintenance and ProvisioningOS – Operating System OSI – Open Systems InterconnectionOSS – Operation and Support SubsystemOVSF – Orthogonal Variable Spreading FactorPDU – Protocol Data UnitRMON – Remote MonitoringSAN – Storage Area NetworkSMTP – Simple Mail Transport ProtocolTMN – Telephone Management NetworkUMTS – Universal Mobile Telecommunications System UTRA – UMTS Terrestrial Radio AccessUTRAN – UMTS Terrestrial Radio Access NetworkWBEM – Web-Based Enterprise ManagementWCDMA – Wideband Code Division Multiple Access WOS – Wireless Office Service

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Chapter I

Data Communication and Network Management Overview

Aim

The aim of this chapter is to:

explain network management system and its challenges•

enlist the functions of network management •

describe technical terminologies of network management system•

Objectives

The objectives of this chapter are to:

elaborate the term communication system•

explain the meaning of term protocol and its functions•

highlight the crucial role of an IT Manager in an organisation•

elucidate the current scenario of network management system•

Learning outcome

At the end of this chapter, the students will be able to:

understand the necessity of network management •

identify various functionalities of network management system•

rea• lise the importance of network management in any organisation

Network Management

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1.1 Introduction In the modern era, computer is one of the elements of technology which increases the efficiency of any organisation. Data communication concept is based on the communication between two computers and exchange of information between them. So a user sitting at a place can communicate easily with other computers through communication channel.

1.2 Data CommunicationGeneral definition of communication means sharing of information between two sources. The sources may be • human being or it may be via any communication channel like telephone, internet etc. Data can be communicated from one system to other system across geographical areas. Data transmission is • nothing but movement of information using some standard methods, like signals along a conductor, optical signals along an optical fibre and so on. For example, in an organisation, a manager wants to send a common mail to his client regarding work status of • project. First of all, he prepares the letter, if his PC is connected to all other PCs. Then through networking, he can send mail to all his clients within a minute. Some of the modern forms of communications include mobiles and e-mails. All these are possible only because of computer networking.

Fig. 1.1 Block diagram of communication system

The source mentioned above is nothing but data which is in the form of raw and it converts into the form of • information after processing.Medium is the signals across a communication and transmission is communication of data achieved by processing • of signals.

1.3 Analogy of Telephone Network ManagementThe need of data and computer communication network management is best described by an analogy of telephone • network management. Telephone network is more reliable which can be illustrated by the following example.The current telephone network is referred to as Public-Switched Telephone Network (PSTN). The reason • behind reliability, quality and performance of telephone network is nothing but proper planning, designing and implementation of good telephone network.

Source (Sender) Medium Receiver

(Sink)

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Fig. 1.2 Telephone model network

There are five levels of network switches and three types of trunks that connect these switches. A trunk is a • logical link between two switches which are connected to one or more physical links. The end office is the lowest layer in the entire architecture model. The customer telephone or Private Branch Exchange is connected to the end office via dedicated link called “loop”. A circuit is connected to set up either directly using local trunk or via higher level of switches and routers. • Primary and secondary route are already programmed into the switch. If the primary route is broken or facilities over primary route are filled to capacity, an alternate route is automatically assigned. The quality of call is regularly measured by trunk maintenance system in terms of Signal-to-Noise Ratio (S/N • Ratio).

1.4 Communication Protocols and Standards Computers transfer data from one source to another source. The procedure of data transmission in the form of • software is commonly known as protocol. Email exchange is possible across the globe because most vendors have adopted internet standard Simple Mail • Transport Protocol (SMTP). Data transmission software or protocols perform the following functions for error free and efficient transmission • of data:

Data fragmentation: � A long message is broken into smaller, fixed size for error free data transmission.Data routing: � It is the process of finding the most efficient route between source and destination before sending the data.

Regional Centre Class 1 Switch

Sectional Centre Class 2 Switch

Primary Centre Class 3 Switch

Toll Centre Class 4 Switch

End Office Class 5 Switch

Regional Centre Class 1 Switch

To OtherRegional CentreSectional CentrePrimary CentreToll CentreEnd Office

Primary CentreToll CentreEnd Office

To Other

To OtherClass 4 Toll PointsEnd Office

LoopDirect TrunkToll-Connecting TrunkToll Trunk

Legend

Sectional Centre Class 2 Switch

Primary Centre Class 3 Switch

Toll Centre Class 4 Switch

End Office Class 5 Switch

Telephone

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Flow control: � All machines are not equally efficient in terms of speed. Flow controls regulate the process of sending data between fast sender and slow receiver. Error control: � Error detecting and recovering is one of the main functions of communication software.

1.5 Network Management: Goals, Organisation and FunctionsNetwork management can be defined in the form of Operations, Administration, Maintenance and Provisioning (OAMP) of network and services.

The operation group is concerned with daily operations in providing network services. • The administration group is concerned with over all goals, policies and procedures of network management.• The maintenance group is concerned with handling functions like installations and repair facilities of • equipments.

1.6 Goal of Network ManagementThe goal of network management is to ensure that the users of network are provided with quality IT services. • To meet this goal, the management should establish a policy to either formally or informally contract an SLA with users. From a business administration point of view, network management involves strategic and tactical planning • of engineering, operations and maintenance of network and network services for current and future needs at minimum overall cost. There should be a well-established interaction between the various groups performing these functions. • Fig. 1.3 presents a top-down view of network management functions. It comprises three major groups: •

network and service provisioning �network and service operations �network I&M �

It is worth considering the different functions as belonging to specific administrative groups, although there are • other ways of assigning responsibilities based on local organisational structure. Network provisioning is the primary responsibility of the engineering group. The customer relations group deals with clients and subscribers in providing services planned and designed by the Engineering group. Network I&M is the primary responsibility of the plant facilities group. Interactions between the groups are • shown in fig. 1.4. Normal daily operations are the function of the network operations group, which controls and administers a NOC. This is the nerve centre of network management operations. The functions of NOC are primarily concerned with network operations; its secondary responsibilities are network • provisioning and network I&M. The associated service operations are handled by a subscriber operation centre (SOC) and customer relations management (CRM). The focus here is on NOC.

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Fig. 1.3 Network management functional groupings

1.6.1 Network Provisioning

Network provisioning consists of network planning and design and is the responsibility of the engineering group. • This group keeps track of new technologies and introduces them as needed. What is needed and when it is needed are determined from analysis of traffic and performance data provided • by the network operations. New or modifications to network provisioning may also be initiated by management decisions. Planned and efficient use of equipment can be achieved with good inventory management of current and future • modifications of network configuration by the network provisioning group. Network management tools are helpful to the engineering group in gathering statistics and studying trends in • traffic patterns for planning purposes. Automated operations systems help in the design of circuits and measuring the performance tune-up.

Network Management

Network Provisioning

Planning

Design

Fault Management/Service Restoration

Configuration Management

Performance Management/Traffic Management

Security Management

Accounting Management

Reports Management

Inventory Management

Data Gathering and Analysis

Fault Management

Trouble Ticket AdministrationNetwork Installation

Network Repairs

Facilities Installationand MaintenanceRoutine Network Tests

Network Operations

Network Maintenance

Network Management

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Fig. 1.4 Network management and functional flow chart

1.6.2 Network Operations and NOC

The functions of network operations listed in fig. 1.4 are administered by the NOC. They are concerned with • daily operations of the network and providing network services.ISO has defined five OSI network management applications, which include–fault, configuration, performance, • security, and account management. They are also responsible for gathering statistics and generating reports for management, system support and • users. NMS and its tools are a necessity for NOC operations.

1.6.3 Network Installation and Maintenance

The Network I&M group takes care of all activities of installation and maintenance of equipment and transmission • facilities. This group is the service arm of the engineering group for installation and fixing troubles for network operations. The group works closely with the help desk in responding to the problems reported from the field. •

1.7 Challenges on Information Technology ManagersManaging a corporate network is becoming harder as it is becoming larger and more complex. When we talk • about network management, it includes not only components that transport information in the network, but also systems that generate traffic in the network. The systems could be hosts, database servers, file servers, or mail servers.In the client–server environment, network control is no longer centralised, but distributed. Computer and • telecommunication networks are merging fast into converged network with common modes and media of transportation and distribution.As in the case of broadband networks, the IT manager needs to maintain both types of networks. Thus, the data • communications manager functions and telecommunication manager functions have been merged to that of the IT manager.

Network

Users

Management Decision

New Technology

Engineering Group-Network Planning

and Design

Installation

Operation Group NOC

-Network Operations

I and M Group-Network Installation

and Maintenance

Performance and Traffic DataTT Restoration

Fault TT

Configuration Data

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With the explosion of information storage and transfer in the modern information era, management of information • is also the responsibility of the IT manager, with the title of CIO, Chief Information Officer. For example, the IT manager needs to worry in detail about who can access the information and what information they can access, i.e., authentication and authorisation issues of security management.The corporate network needs to be secured for privacy and content, using firewalls and encryption. Technology • is moving so fast and corporate growth is so enormous, that a CIO has to keep up with new technologies and the responsibility for financial investment that the corporation commits to. Top challenging activities in managing the network include:

rapid advance of technology �problem analysis—needs human intuition and skill besides sophisticated management tools �anticipate customer demands �acquire and retain human resources �manage client–server environment in converged networks �networking with emerging technology necessitates the need for continuing education �collaborative research between academic institutions and industry �maintain reliability, that is, make changes, upgrades, etc. without disrupting the network and impacting �businessdiagnose problems or outages in a non-disruptive manner (without impacting other users on the network) �estimate the value of a technology transition, for example, should one transition over to accommodate the �increasing number of IP addresses with IPv6 or continue with IPv4 with Network Address Translation (NAT) as a hierarchical addressing scheme

1.8 Current Trends in Network ManagementIn current NMS, there are several limitations. One of the limitations of SNMP-based management system is • that values of managed objects should be defined as scalar value. With the proliferation of the Internet, secured network and communication has become extremely important. • Existing management standards do not go far enough in this. However, security management has taken on the role of a special topic in network management.Topics of high interest in this field are firewalls that establish secure networks and cryptography that assure secure • communication. IT itself is exploding and giving rise to new challenges for expanding the horizon of network management. Transport of voice, video and data is integrated in broadband multimedia services. Broadband multimedia service is based on ATM, IP and MPLS in a WAN and several emerging access technologies such as HFC, Asymmetric Digital Subscriber Loop (ADSL) and fixed and mobile wireless. Quality of service in integrated services is important.

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Summary General definition of communication means sharing of information between two sources. The source may be a • human being or it may be via any communication channel like telephone, internet etc. Data can be communicated from one system to other across geographical areas.The reason behind reliability, quality and performance of telephone network is nothing but proper planning, • designing and implementation of good telephone network. A trunk is a logical link between two switches which are connected to one or more physical links. The end • office is the lowest layer in the entire architecture model. The customer telephone or private branch exchange is connected to the end office via dedicated link called “loop”. Computers transfer data from one source to another . The procedure of data transmission in the form of software • is commonly known as protocol. Email exchange is possible across the globe because most vendors have adopted Internet standard Simple Mail Transport Protocol (SMTP). Managing a corporate network is becoming harder as it becomes larger and more complex. When we talk about • network management, it includes not only components that transport information in the network, but also systems that generate traffic in the network. Network management can be defined in the form of Operations, Administration, Maintenance and Provisioning • (OAMP) of network and services. The goal of network management is to ensure that the users of network are provided with quality IT services. • To meet this goal, the management should establish a policy to either formally or informally contract an SLA with users.From a business administration point of view, network management involves strategic and tactical planning • of engineering, operations and maintenance of network and network services for current and future needs at minimum overall cost.

References Data Communication and Network. Available at: <http://www.nios.ac.in/srsec330/330L5.pdf>• Mani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.

Recommended ReadingMark Burges, • Principles of Network System Administration, Wiley Dreamtech.Morris, • Network Management, Pearson Education.Paul, • Distributed Network Management, John Wiley.

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Self Assessment

Data communication concept is based on the __________between two computers and exchange of information 1. between them.

communicationa. interactionb. interconnectionc. data exchanged.

What is the meaning of communication?2. Sharing of informationa. Collection of informationb. sending of informationc. Using of informationd.

Data transmission can be termed as _________.3. movement of dataa. piling of datab. gathering of datac. collection of datad.

Now days the telephone network is referred to as ____________.4. PSTNa. NMSb. NOCc. TMNd.

Which of the following is the limitation of SNMP?5. Objectsa. Values of managed objectb. Value systemc. NMsd.

What does ADSL stand for?6. Asymmetric Digital Subscriber Loop a. Asymmetric Digital Subscriber Line b. Asymmetric Digitised Subscription Link c. Asymmetric Distance Subscriber Linkage d.

Managing a corporate network is becoming __________ as it is getting larger and more complex.7. complexa. harderb. simplec. manageabled.

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Daily operations in providing network services are based on _______________.8. operation managementa. service managementb. quality managementc. risk managementd.

The __________ is concerned with administrating over all goals, policies, and procedures of network 9. management.

administration groupa. operation groupb. quality groupc. service groupd.

ISO has defined five OSI network management applications. Which of the following is not one of them?10. Faulta. Configurationb. Performancec. Assessmentd.

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Chapter II

SNMPV Network Management

Aim

The aim of this chapter is to:

give a brief history of SNMP•

explain the network management protocol•

underdstand various SNMP versions and about SNMP requests and monitoring of network•

Objectives

The objectives of this chapter are to:

illustrate the key components of SNMP•

enlist the model network for various network component•

explain the SNMP request and response management system•

enlist the threats in network management•

Learning outcome

At the end of this chapter, the students will be able to:

understand the necessity of SNMP for network management system•

identify various versions of SNMP•

recognise threats to network security•

id• entify various requirements of network management system

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2.1 IntroductionSimple Network Management Protocol is the protocol developed to manage nodes like server, workstation, switches, hubs, etc., on IP network. SNMP is an application protocol. A SNMP managed network consists of three key components

Managed device:• It is a device which helps in information sharing in both unidirectional and bidirectional. Theses managed devices are like servers, switches, IP telephone, IP video cameras, computer hosts and printers. Agent software resides on managed device:• An agent has knowledge management information which translates the information into SNMP specific form. SNMP software model is responsible for handling configuration of network devices. Network management system:• It is a combination of hardware and software used to monitor and administer a network.

2.2 SNMP HistorySNMP was defined in the late eighties, with the first implementations appearing in the end of 1988. The original • version of the protocol—SNMPv1— contained the five request/response primitives:

GetRrequest �SetRequest �GetNext- Request �Get-Response �Trap �

The second incarnation of SNMP appeared in 1993, and was an ambitious attempt to address a number of • deficiencies in SNMPv1 as well as adding new features. Implementations of this new standard did however reveal a number of problems that lead to a major revision of the specifications, with a less comprehensive set of features added.The new SNMPv2 specification was released in 1996, and introduced a locking mechanism, 64-bit counters • and improved error reporting.The most recent addition to the protocol is named SNMPv3. It is basically SNMPv2 with a number of security • additions like a Security Model and an Access Control Model. The specification documents also describe an overall architecture for describing SNMP management frameworks • and a model for message processing and dispatching.

2.3 SNMP Model NetworkThe SNMP model network includes following components:

Management station:• The management station is a standalone device which translates management task into actual command sent over the network. Management agent: • It is a software module which resides on the managed device. It responds to the actions requested by network management station. It is basically resides on the network device such as switches, routers, firewalls and gateways etc. Management information base:• The managed information consists of objects and the objects are of predefined type. The collection of objects on a specific device is called as Management Information Base (MIB). Each type device has its own MIB, like Printer MIB, UPS MIB. Network management protocol: • This protocol is used for management of TCP/IP in SNMP. Usually, it runs over UDP that means retransmission is handled by SNMP station and agent.

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Fig. 2.1 SNMP concept

SNMP model defines two entities called client – server. The server is called as an agent, located on device. The • client part is SNMP manager, which is in charge of data collection. The SNMP control unit of SNMP Agent Platform comprises of generic module for sending and receiving SNMP • message using User Datagram Protocol (UDP). The SNMP Control Unit has a main loop which is called as processing function. For each managed object • identified in the SNMP message, the processing function looks for the corresponding object representation in the MIB image and triggers the associated access method located in the managed resource interface. The processing function of SNMP is responsible for the implementation of all mechanisms associated with the • SNMP protocol. Therefore, the arrived SNMP message is correctly formatted by the processing function with the information provided by the access method.

Protocol Structure - SNMP Simple Network Management ProtocolSNMP is an application protocol, which is encapsulated in UDP . The general SNMP message format for all versions is shown below:

Version Community PDU

Version:• SNMP version number. Both the manager and agent must use the same version of SNMP. Messages containing different version numbers are discarded without further processing.Community:• Community name used for authenticating the manager before allowing access to the agent.PDU (Protocol Data Unit):• The PDU types and formats are different for SNMPv1, v2 and v3, which will be explained in the corresponding sections.

2.3.1 SNMP RequestsThere are three types of SNMP requests

GetRequest• : It is used to retrieve one or more values from an agent.SetRequest• : It is used to set values within a device.

SNMP Manager

SNMP Request

SNMP Resposes

SnMP TRaps

Devices withSNMP Agent

Routers

Hosts

Switch

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GetNextRequest• : It is used to retrieve next value from the table or a list within an agent.

Similarly, there is a SNMP response:GetResponse• : It informs the management station to give result of GetRequest. Trap messages are sent from agent to managers. These messages notify the manager about agent’s state.

2.3.2 Monitoring of NetworkThere are many devices and operating systems which monitor network. These are:

Core network devices (routers, switches, hubs, bridges, and wireless network access points)• Operating systems• Consumer broadband network devices (cable modems and DSL modems)• Consumer electronic devices (cameras and image scanners)• Networked office equipment (printers, copiers, and FAX machines)• Network and systems management/diagnostic frameworks (network sniffers and network analysers)• Uninterruptible Power Supplies (UPS)• Networked medical equipment (imaging units and oscilloscopes)• Manufacturing and processing equipment•

2.4 Versions of SNMPThere are various version of SNMP which are used to communicate between agent and manager. Version 1 is the initial implementation of SNMP.

2.4.1 SNMPv1SNMPv1 is a simple request/response protocol. In the SNMPv1 framework, the network-management system installed a request, and managed devices return responses.

Protocol structureThe format for GetRequest, GetNext Request, GetResponse and SetRequest PDUs is shown here.

PDU type Request ID Error status Error index Object 1, value 1 Object 2, value 2 ...

PDU type: � Specifies the type of PDU transmitted: 0 GetRequest, 1 GetNextRequest, 2 GetResponse and 3 SetRequest.Request ID: � Associates SNMP requests with responses.Error status: � Indicates one of a number of errors and error types. Only the response operation sets this field. Other operations set this field to zero.Error index: � Associates an error with a particular object instance. Only the response operation sets this field. Other operations set this field to zero.Variable bindings: � Serves as the data field of the SNMPv1 PDU. Each variable binding associates a particular object instance with its current value (with the exception of Get and GetNext requests, for which the value is ignored).

The format of the Trap PDU is shown below:

PDU type Enterp Agent Addr Gen Trap Spec Trap Time Stamp Obj 1, Val 1 Obj 1, Val 1 ...

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PDU type: � Specifies the type of PDU (4=Trap).Enterprise: � Identifies the management enterprise under whose registration authority the trap was defined.Agent address: � IP address of the agent, used for further identification.Generic trap type: � Field describing the event being reported. The following seven values are defined:Specific trap type: � Used to identify a non-generic trap when the Generic Trap Type is enterprise specific.Timestamp: � Value of the sysUpTime object, representing the amount of time elapsed between the last (re-)initialisation and the generation of that Trap.

The basic SNMP has very primitive security functions. The only mechanism to authenticate a manager is by so • called community name (also called community string). The community name is used in defining management groups with differing access rights. That is, the community name is used to define which managers are allowed to submit get or set requests. The same community name mapping is used to define access policies for different managers. That is, some • names may be restricted to operate only on some the areas of MIB while the others may have greater rights.The SNMP community is locally defined at a node and the same name may be used at multiple nodes. When a • manager wants to perform some kind of management task (get or set) it always has to present the community name that matches its need for access rights. In order to manage a selection of nodes the manager has to maintain a list of all the relevant community names.

2.4.2 SNMPv2The SNMPv2 standardisation wasn’t successful. The standardisation process resulted in three mutually �incompatible standards (SNMPv2 party-based, SNMPv2u and SNMPv2).Originally, the specification and designing of the SNMPv2 was initiated to enhance SNMP functionalities �and the security was given some priority. A security scheme called “Party-Based Security” was introduced. Because the original SNMPv2 proposal �was never really taken into any broader use, the Party-Based Security Model isn’t introduced here. The standardisation process of SNMPv2 was stuck with two competing proposals: SNMPv2u, SNMPv2 �which both had a user-based security model. Unfortunately, a compromise was made and a proposal named SNMPv2c was standardised.

Protocol StructureThe general format for all SNMP versions is similar except the format of PDU (Protocol Data Unit). The format of the PDU for SNMPv2 is displayed here. For SNMPv2, Get, GetNext, Inform, Response, Set, and Trap PDUs have the following format:

PDU type Request ID Error status Error index Object 1, value 1 Object 2, value 2 ...

PDU type � : Identifies the type of PDU transmitted (Get, GetNext, Inform, Response, Set, or Trap).Request ID � : Associates SNMP requests with responses.Error status � : Indicates one of a number of errors and error types. Only the response operation sets this field. Other operations set this field to zero.Error index � : Associates an error with a particular object instance. Only the response operation sets this field. Other operations set this field to zero.Variable bindings � : Serves as the data field (value 1, value 2¡ ) of the SNMPv2 PDU. Each variable binding associates a particular object instance with its current value (with the exception of Get and GetNext requests, for which the value is ignored).

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2.4.3 SNMPv3 - The Security Extension

Using SNMPv3, users can securely collect management information from their SNMP agents without fear that • the data has been tampered with. Also, confidential information, such as SNMP set packets that change a device’s configuration, can be encrypted to prevent their contents from being exposed on the wire. Also, the group-based administrative model allows different users to access the same SNMP agent with varying • access privileges.Basically, the effective PDU, that is either SNMPv1-PDU or SNMPv2-PDU, is encapsulated in a SNMPv3 • packet. This encapsulation provides security related functions on the level of message processing.In SNMPv3, each entity–manager and agent–contains a single SNMPv3 engine to perform the message • processing. When an application wants to send SNMP PDUs to the node in the network the following happens: •

The engine first accepts the SNMP datagram to be sent from SNMP application level, performs the appropriate �security functions, encapsulates the PDU into a SNMPv3 message and then transmits the message to the network. When the engine receives a SNMPv3 message from the network, it performs the necessary decryption and �authentication functions before passing the PDU to the SNMP applications.

Protocol Structure - SNMPv3 message format:

Msg Processed by MPM (Msg Processing Model)

Version ID Msg Size Msg Flag Security Model

Msg Processed by USM (User Security Module)

Authoritative

Engin ID

Authoritative

Boots

Authoritative

Engine Time

User name

Authentication parameters

Privacy Parameter

Scoped PDU

Context engine ID Context name PDU

Versio � n: For SNMPv3 it is 3.ID: � A unique identifier used between two SNMP entities to coordinate request and response messagesMsg Size: � Maximum size of a message in octets supported by the sender of the messageMsg Flags: � An octet string containing three flags in the least significant three bits: reportableFlag, privFlag, authFlag.Security Model � : An identifier to indicate which security model was used by the sender and therefore which security model must be used by the receiver to process this message.AuthoritativeEngineID: � The snmpEngineID of the authoritative SNMP engine involved in the exchange of this message. Thus, this value refers to the source for a Trap, Response, or Report, and to the destination for a Get, GetNext, GetBulk, Set, or Inform.AuthoritativeEngineBoots: � The snmpEngineBoots value of the authoritative SNMP engine involved in the exchange of this message.AuthoritativeEngineTim � e: The snmpEngineTime value of the authoritative SNMP engine involved in the exchange of this message.User Name: � The user (principal) on whose behalf the message is being exchanged.AuthenticationParameters � : Null if authentication is not being used for this exchange. Otherwise, this is an authentication parameter.

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PrivacyParameters: � Null if privacy is not being used for this exchange. Otherwise, this is a privacy parameter.PDU (Protocol Data Unit): � The PDU types for SNMPv3 are the same as the SNMPv2.

2.5 Threats in Network SecurityDescribed below are various threats in network management.

2.5.1 Masquerading

It means the attackers can do anything on behalf of authorised person i.e., manager. He can access any information • and also can change or modify vital documents or information. Spoofing is the one way to Masquerading. Spoofing means replacing the IP address information packets into the fake information. Each packet contains • the original IP address and its information. By replacing the original IP address with a fake one a hacker can mask the true source of an attack or force the • destination of an IP address to reply to a different machine.

2.5.2 Changes of Information

It means the original message can be changed by the third party. The changed message is passed to the original • receiver. Now the receiver of message thought that the message is sent by trusted person. In network management, an authorised network manager can generate a valid management protocol data unit • (PDU). If an attacker succeeds to intercept the transmission, the whole PDU can be changed while keeping the authentication information unchanged.

2.5.3 Changes in Message Stream

It means that the stream of messages is modified somehow. This means that the messages could be reordered, or • the messages could be recorded and replayed. The network management design originally aimed to connectionless management protocols.Most of the management protocols were designed to operate on connectionless transport services the message • stream modification is a severe threat in network management. An attacker could for example record the valid management message that orders the router to shut down. Then, • in the future, the attacker could use the captured message to perform the router shutdown whenever he wanted to do so.

2.5.4 Disclosure

The threat of disclosure means that confidential information is leaked to the people who shouldn’t see it. In • network security in general, sniffing the traffic that is not encrypted is one way to do it. Also, in network management, some management PDUs can carry some crucial information about the network • and managed nodes itself. So, if an attacker spies the management traffic in a network segment, he could get some important information. That information could be used as the basis for other attacks, such as masquerading. A way to fight the threat of disclosure is to encrypt the messages.

2.5.5 Block of Service

It means that some network service will become blocked somehow. Attacker could for example try to open TCP • connections to a host continuously and that way block all the other connection requests. In network management this could mean that an attacker succeeds in blocking the flow of management protocol • messages between the manager and the agent.In the network management, the Block of Service (BoS) can also be a consequence if the other threats take • place. For example, if an attacker succeeds to masquerade and act as the network manager, he can possibly give the shutdown command to a specific router.

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2.5.6 Ignorance of Message

It is a threat where the information contents of the messages are ignored. Instead, the crucial information of the • system is extracted from the usual patterns of the traffic flow. These last two threats are hard to prevent.

2.6 Information ModelIn the present scenario, technology plays an important role in increasing the efficiency of an organisation. • Information is one of the vital entities for any kind of organisation. Companies are using advanced technology like XML (Extended Markup Language) to give some structure to any unstructured information. Content is nothing but information required for smooth running of any organisation. So information model is • one of the content management tools. Information model helps in organising the content so that it can be used in innovative way for organisational • growth. Once the information model is developed for the content then it will enhance the storing, retrieving functions of information. Important actions to be taken into consideration are:•

Analysis: � Analyse the target group or individual who requires the information resource in their day to day life.Proper planning: � Planning means how information reach to the needy people and in which way they will be benefited from this information.Feedback: � This means the response from the user who uses the information.

Information model comprises of various parts, for example, information about resources is one part of information • model. Similarly, categorising in corporate training materials, technical and sales are other parts of information model. The information model also includes business cycle, sales, policies, procedures, processes, day to day business • analysis, stakeholder’s information and so on. One should plan what to include and what to exclude, in content by considering various scenario and the level • of information. Size of the information model depends upon the organisation. Sometimes the information model is very vast which stretches across entire organisation and sometimes it is • very small because of limited scope.

2.6.1 Three Tiered Model of Information

The information model has a three-tier structure. At base, the first tier consists of the dimensions that identify • how information will be categorised and labelled for both, internal and external use in organisation. The second tier sorts information assets into information types. This provides authors with the basis for creating • well-structured modules that represent a particular purpose in communicating informationThe third tier provides structure for each information type, outlining the content units that authors use to build • information types.

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Fig. 2.2 Three tier model of information

Metadata Dimensions

Information Types

ContentUnit

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Summary Simple Network Management Protocol is the protocol developed to manage nodes like server, workstation, • switches and hubs etc on IP network. SNMP is an application protocol. An SNMP managed network consists of three key components–managed device, agents, and network management • system.SNMP was defined in the late eighties, with the first implementations appearing in the end of 1988. The original • version of the protocol—SNMPv1— contained the five request/response primitives: GetRrequest, SetRrequest, GetNext- Request, Get-Response, and trap.The basic SNMP has very primitive security functions. The only mechanism to authenticate a manager is by so • called community name. The community name is used in defining management groups with differing access rights. Various threats in network management are like masquerading, changes of information, changes in message • stream, disclosure, block of service, ignorance of message.The SNMP model network includes management station, management agent, management information base, • network management protocol.In the present scenario, technology plays an important role in increasing the efficiency of an organisation. • Information is one of the vital entities for any kind of organisation. Information model helps in organising the content so that it can be used in innovative way for organisational • growth. Once the information model is developed for the content then it will enhance the storing, retrieving functions of information.

ReferencesData Communication and Network. Available at: <http://www.nios.ac.in/srsec330/330L5.pdf> Last accessed • 15th February 2011.Information Model Architecture. (2008), Available at: <. http://www.esv.se/download/18.6dae77a0113497f158• 680002589/NES+Information+Model+Architecture+-+Version+2.pdf> Last accessed 15th February, 2011.Interpeak. Simple Network Management Protocol., (2005). Available at: <http://www.interpeak.com/files/snmp.• pdf> Last accessed 15th February, 2011. SNMP Concept. Available at: (2008).<http://www.loriotpro.com/Products/On-line_DocumentationV3/• LoriotProV3Doc/C3-Introduction_to_Network_Supervision/C3-B2_SNMP_Concepts.htm> Last accessed 15th February, 2011.SNMP: Simple Network Management Protocol. Available at: < http://www.javvin.com/protocolSNMP.html> • Last accessed 1st March 2011.

Recommended ReadingMani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.Mark Burgess, (2004). • Principles of Network and System Administration. Wiley Dreamtech. 634 pages.

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Self Assessment

The management ____________ is a standalone device which translates management task into actual command 1. sent over the network.

information basea. network managementb. protocolstation c. agentd.

The third tier provides ________ for each information type.2. structurea. domainb. framec. qualityd.

What does XML stand for?3. Extended Markup Languagea. Expanded Markup Languageb. Elaborated Markup Languagec. Explicit Markup Languaged.

Which of the following is important for information model?4. Analysisa. Costb. Actionc. Communicationd.

How many request/response primitives does the SNMPv1protocol contain?5. Fivea. Sixb. Fourc. Threed.

_____________ is used for management of TCP/IP in SNMP. 6. Network management protocol a. Station b. Agentc. Information modeld.

How many types of SNMP request are there?7. Onea. Twob. Threec. Fourd.

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The trap messages are sent from ____________.8. agent to managera. manager to managerb. manager to agentc. agent to agentd.

_____________informs the management station to give result of GetRequest.9. GetResponsea. SetResponseb. GetRequestc. SetRequestd.

The SNMP control unit of SNMP Agent Platform comprises of generic module for sending and receiving SNMP 10. message using ___________.

UDPa. NMSb. SNMPv2c. SNMPv1d.

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Chapter III

Remote Monitoring

Aim

The aim of this chapter is to:

explain the basic concept of remote monitoring•

enlist nine RMON groups•

give an introduction to ATM remote monitoring system•

Objectives

The objectives of this chapter are to:

give an overview of remote monitoring•

discuss RMON groups of monitoring elements•

portray basic feature of ATM remote monitoring •

Learning outcome

At the end of this chapter, the students will be able to:

understand what is remote monitoring•

identify RMON groups of monitoring element•

know a• bout remote monitoring features in ATM

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3.1 Remote MonitoringRemote Monitoring (RMON) is a standard monitoring specification that enables various network monitors and console systems to exchange network-monitoring data. RMON provides network administrators with more freedom in selecting network-monitoring probes and features that meet their particular networking needs.

The RMON specification defines a set of statistics and functions that can be exchanged between RMON-compliant console managers and network probes. As such, RMON provides network administrators with comprehensive network-fault diagnosis, planning and performance-tuning information. Figure below illustrates an RMON probe capable of monitoring an Ethernet segment and transmitting statistical information back to an RMON-compliant console.

Fig. 3.1 RMON probe

3.2 RMON GroupsRMON delivers information in nine RMON groups of monitoring elements, each providing specific sets of data • to meet common network-monitoring requirements.Each group is optional so that vendors do not need to support all the groups within the Management Information • Base (MIB). Some RMON groups require support of other RMON groups to function properly.There are 2 versions of RMON: •

RMON1 is defined as10 MIB groups for basic network monitoring. �RMON2 (RMONv2) is an extension of RMON that focuses on higher layers of traffic above the medium �access-control (MAC) layer. RMON2 has an emphasis on IP traffic and application-level traffic it also allows network management applications to monitor packets on all network layers.

RMON Groups Function Elements

Statistics Contains statistics measured by the probe for each monitored interface on this device.

Packets dropped, packets sent, bytes sent (octets), broadcast packets, multicast packets, CRC errors, runts, giants, fragments, jabbers, collisions, and counters for packets ranging from 64 to 128, 128 to 256, 256 to 512, 512 to 1024, and 1024 to 1518 bytes.

RMON - compliantconsole manager

RMON - probe

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History Records periodic statistical samples from a network and stores them for later retrieval.

Sample period, number of samples, items sampled.

AlarmPeriodically takes statistical samples from variables in the probe and compares them with previously configured thresholds.

Includes the alarm table and requires the implementation of the event group. Alarm type, interval, starting threshold, stop threshold.

Host Contains statistics associated with each host discovered on the network.

Host address, packets, and bytes received and transmitted, as well as broadcast, multicast, and error packets.

HostTopN

Prepares tables that describe the hosts that top a list ordered by one of their base statistics over an interval specified by the management station. Thus, these statistics are rate-based.

Statistics, host(s), sample start and stop periods, rate base, and duration.

Matrix Controls the generation and notification of events from this device.

Event type, description, last time event sent.

FiltersIt helps in matching packets by filter equations. These packets form a data stream which might be captured or generates events.

Bit-filter type (mask or not mask), filter expression (bit level), conditional expression (and, or, not) to other filters.

Packet capture

Enables packets to be captured after they flow through a channel.

Size of buffer for captured packets, full status (alarm), and number of captured packets.

Events Controlling of events from this device. Event type, description, last time event sent.

Table 3.1 RMON monitoring group

3.3 ATM Remote Monitoring The remote ATM monitor is a low-cost PC-based cell capture device. Cells are captured and their arrival times • are recorded by a specially designed network interface card, known as Dag. This card consists of an ATM physical layer interface, a large FPGA, an ARM RISC processor, and a PCI bus interface.The card is linked into the ATM network by an optical coupler or resistive matching network which non-• intrusively duplicates all the cells. The monitor hardware and software are capable of capturing cell headers, payload CRCs and arrival times at full OC3 rates that is about 300,000 cells per second. However, the volume of data that can be sent back to the central analysis site is limited by the bandwidth of the • return link. The Dag can filter cells by VPI and VCI, so that only subsets of the cell flow are returned, and data compression techniques in the PC are used to reduce the return data flow to a minimum.Serial cell data received from the ATM link is assembled into cell buffers that contain both the cell payload and • header. At the start of each cell a time-stamp is generated from the local 4 MHz clock, and this is also written into the cell buffer. During cell reception a 32-bit CRC is calculated over the cell payload, this CRC is written into the cell buffer • when a complete cell has been received. The on-board processor can read all of the cell data, or just a sub-set, such as cell header and arrival time-stamp. The heart of the cell capture card is a large FPGA (10,000 gate equivalents), which can be programmed from the • PC. An outline diagram of the normal FPGA configuration for cell arrival time measurement is shown below.

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GPS time pulse

ATM cells

Internal 32-bit bus

16-word cell buffers

ARMprocessorbus

Time-stamp pgenerator

Payload CRCgenerator

Cell multiplexerand filter

Fig. 3.2 ATM remote monitoring

The GPS time receiver produces a time pulse each second, synchronised to UTC with an accuracy of 100 nsec. • Shortly after each time pulse, an ASCII time information packet is output by the receiver, this gives the UTC time and date for that second and other receiver management information; this time packet is received directly by the PC through a serial port. At the leading edge of the time pulse the local clock is loaded into the GPS register in the FPGA, and an interrupt • is generated to the on-board ARM processor. This processor can in turn interrupt the PC and copy the GPS time register value into PC memory. The on-board clock signal, unfortunately, drifts by many microseconds in the one second intervals between • GPS pulses. However, careful interpolation allows this drift to be corrected to give a final accuracy of about 250 nsec compared to UTC.The remote monitor software running in the PC acts as a server which can connect to an analysis client by • TCP/IP. Thus the client may be geographically remote from the monitor server, making its connection over the Internet. Also, an analysis client may connect with two or more remote monitors, in order to correlate cell streams measured at different points in the network.The monitor software receives buffers of cell data-cell header, time stamp and CRC - from the Dag at intervals • of one second. These data are compressed and transmitted to the client together with the GPS register value and information from the GPS time packet that will allow the client to correct the cell time-stamps to UTC. These corrections are not made in the monitor. The monitor software can also receive cell filter requests from the client, and load these into the Dag. The monitor • has been designed to run unattended, and has been implemented under both DOS and LINUX.

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SummaryRemote Monitoring (RMON) is a standard monitoring specification that enables various network monitors and • console systems to exchange network-monitoring data. RMON provides network administrators with more freedom in selecting network-monitoring probes and consoles with features that meet their particular networking needs.With Remote Monitoring we can collect almost any type of needed operational data from the connected • system.RMON delivers information in nine RMON groups of monitoring elements, each providing specific sets of • data to meet common network-monitoring requirements. Each group is optional so that vendors do not need to support all the groups within the Management Information Base (MIB).The remote ATM monitor is a low-cost PC-based cell capture device. Cells are captured and their arrival times • recorded by a specially designed network interface card, known as the Dag. This card consists of an ATM physical layer interface, a large FPGA, an ARM RISC processor, and a PCI bus interface.

ReferencesInternetworking Technologies (2008). Available at: <http://faculty.kfupm.edu.sa/coe/marwan/richfiles/• Chapter%2055%20%28Remote%20Monitoring%29.pdf> Last accessed 15th February 2011.Mark Burgess, (2004). • Principles of Network and System Administration. Wiley Dreamtech. 634 pages.

Recommended ReadingData Communication and Network. Available at: <http://www.nios.ac.in/srsec330/330L5.pdf> Last accessed • 15th February 2011.Mani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.Morris, • Network Management, Pearson Education.Paul, • Distributed Network Management, John Wiley.

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Self Assessment

___________ is a standard monitoring specification that enables various network monitors and console systems 1. to exchange network-monitoring data.

RMONa. NMSb. PSTNc. NOCd.

_________ specification defines a set of statistics and functions that can be exchanged between RMON-compliant 2. console managers and network probes.

RMONa. NMSb. PSTNc. NOCd.

The remote monitor software running in the PC acts as a server which can connect to an analysis client by 3. __________.

TCP/IPa. HTTPb. FTPc. RMONd.

Which statement is true?4. Information will be collected from the monitored systems remotely.a. Information will be collected from the monitored systems directly.b. Information will be collected from the monitored systems systematically.c. Information will be collected from the monitored systems frequently.d.

At the leading edge of the time pulse the local clock is loaded into the GPS register in the _____________.5. RMONa. FPGA b. UMTSc. FTPd.

RMON delivers information in ______ RMON groups of monitoring elements. 6. ninea. sixb. sevenc. fived.

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Which of the following group is optional so that vendors do not need to support all the groups?7. MIBa. NMSb. TOCc. TMNd.

The remote __________ monitor is a low-cost PC-based cell capture device.8. ATMa. NMSb. TOCc. TMNd.

CRC is of how many bits in ATM?9. 32a. 8b. 64c. 16d.

What enables to monitor features of newly released products, something not found in most off the shelf 10. products?

Free toola. Merge developed toolb. Fix toolc. Quality toold.

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Chapter IV

Telecom Management Network

Aim

The aim of this chapter is to:

explain the TMN functional model•

elucidate the OSI function in TMN•

illustrate TMN logical model•

Objectives

The objectives of this chapter are to:

give a brief introduction to telecom management network•

explain TMN functional models like OS, MD, WS•

describe TMN logic model and TMN solution•

Learning outcome

At the end of this chapter, the students will be able to:

understand the importance of telecom management•

identify the standards of telecom management network•

analyse• the TMN logic model

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4.1 Telecom Management NetworkThe network provided by Telecom Management Network is flexible, scalable, reliable and easy to enhance. TMN provides more capable and flexible networks by defining standard ways of doing network management. TMN allows process to be distributed to appropriate levels of scalability and communication efficiency.

TMN principles are incorporated into telecommunication network to send and receive information and to manage its resources. A telecommunication network is comprised of switching systems, circuits, terminal, etc. In TMN terminology, these resources are referred to as Network Elements (NE). TMN enables communication between operations support systems and NEs.

Fig. 4.1 Connections between TMN(Source: International Engineering Consortium. http://180.151.36.4/quality/TelecomBasics/tmn.pdf)

4.2 TMN StandardIn International Telecommunication Union (TMN) is defined as Telecommunication Services Sector. The TMN architecture and interfaces are built on existing open system interconnection standard. The standards are like:

CMIP (Common Management Information Protocol) which defines management services exchange between • peer entities. GDMO (Guideline for Definition of Managed Object) provides templates for classifying and describing managed • resources.ASN.1 (Abstract Syntax Notation One) provides syntax rules for data types.• Open system interconnect reference model defines the seven layers of OSI reference model.•

TMN

Tele

com

mun

icat

ions

Net

wor

k

OS

OS

OS

Data Communications Network

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4.2.1 TMN, OSI and Management

TMN is based on the OSI management frame work and use object oriented approach with managed information • in network resources. Network managed information, as well as the rules by which the information is presented and managed, is • defined as Management Information Base (MIB). Processes which are used in this information are called as management entities. There are two possible roles: manager and agent. Manager and agents processes send and receive requests and • notifications using the CMIP.

4.2.2 TMN SolutionsIndependent software vendors and service providers need to deploy TMN solutions that will:

reduce time to market• reduce cost• support increasing demands for higher quality• adhere to industry standards of TMN•

4.3 The TMN Functional ModelThe TMN provides telecommunication service to various operating system and telecommunication network. There are many building blocks in TMN.

Fig. 4.2 TMN building blocks(Source: International Engineering Consortium. http://180.151.36.4/quality/TelecomBasics/tmn.pdf)

TMNWS

OS DCN

MD

NE QA

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The blocks are like:OS - Operating System• MD - Mediation Device• QA - Q Adapters• WS - Work Stations•

System components Descriptions

OSControls telecommunication and management functions. Performs system operation functions. Provide some of the mediation and Q adaptation.

MD Provides mediation between local TMN interface and OS information model. Mediation functions can be implemented across hierarchies of MDs.

QAIt translates between TMN and non TMN interfaces. A TL 1 Q adapter translates between a TL1 ASCII message based protocol and the CMIP.

NE

It contains manageable information which is monitored and controlled by an OS. An NE must have standard TMN interface. If it does not have standard TMN interface then it can be stilled managed by Q adapter.The Ne provides the operating system with representation of manageable informa- tion and functionality.The actual NE also contains its own OS functions and QA functions.

WS It performs workstation functions. It translates information between TMN format and displayable format for the user.

Table 4.1 System components

4.4 OSI Function in TMNStack support: • TMN defines Message Communication Function (MCF). All building blocks are having MCF. It can provide all seven layers and also can provide protocol convergence functions for interface.Manager and agent roles:• TMN function blocks can act in a role of manager or agent. The manager and agent concept is same as OSI and CMIP management. Managers processes issues directives and receive notifications, whereas agent process carries out directives and send responses.

TMN interfaces are as follows:

Interfaces Description

QQ is the interface between two TMN. QX carries information that is shared between the MD and NE that it supports. It is exists between NE and MD, QA and MD and MD and MD. Q3 interface is the OS interface.

F F exists between WS and OS, and between WS and MD

X X interface exists between two TMN-conformists OS in two separate domains.

Table 4.2 TMN interfaces

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Fig. 4.3 Standard interface between TMN components(Source: International Engineering Consortium. http://180.151.36.4/quality/TelecomBasics/tmn.pdf)

4.4.1 Q InterfaceThere are two classes of Q interfaces:

Q• 3 Interface: It is the important part of any operating system. It is the only interface which uses QA, MDs and NEs to communicate directly with the OS. Q• X Interface: QX interface always communicate with MD. It never takes the place of a Q3 interface. The MD can interpret between local management information provided by a QX interface and the OS information provided by Q3 interface.

Fig. 4.4 Q interfaces(Source: International Engineering Consortium. http://180.151.36.4/quality/TelecomBasics/tmn.pdf)

q3

q3q3

q3 q3q3

q3

q3OSFOSF

MFMF

NEFNEF QAFQAF

qxqx

qxqxqx

qx

m

x

m

Q3 interface

OS

MD QA NE

NEQA

Qx interface

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4.5 TMN Logical ModelTMN supplies a model of logical layer which defines or suggest the management level for specific functionality. There are mainly two levels named highest level and lower level.

Highest level:• It manages corporate and enterprise goals.Lower Level:• It is defined by network or network resources.

Fig. 4.5 TMN logical model

Following are the areas concerned with each logical layer:BML

high level planning• budgeting• goal setting• executive decision• business level agreement•

SMLUses information presented by NML to manage contracted services to existing and potential customer.• It is also a key point for interaction with service providers and with other administrative domain.• Maintaining of statistical data to support quality of services.•

NMLIt has the visibility of entire network based on NE information presented by EML OSs.• NML manages individual NEs and NEs as a group.• NML coordinates all network activities and supports the demand of SML. •

EMLIt manages the network elements.• It has an element manager who is responsible for TMN manageable information.• Logically, all MDs are in EML. Even when they are physically located or in some other logical layer.•

NELIt presents the TMN manageable information in an individual NE. Both the Q adapter, which adapts between • TMN and non-TMN information, and NE are located in NEL. NEL interfaces between the manageable information and TMN infrastructure.•

BML

SML

NML

EML

NEL

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SummaryThe network provided by TMN is flexible, scalable, reliable, and easy to enhance. TMN provides more capable • and flexible networks by defining standard ways of doing network management. TMN allows process to be distributed to appropriate levels of scalability and communication efficiency. In International Telecommunication Union TMN is defined as Telecommunication Services Sector. The TMN • architecture and interfaces are built on existing open system interconnection standard.TMN is based on the OSI management frame work and use object oriented approach with managed information • in network resources. Network managed information, as well as the rules by which the information is presented and managed, is defined as Management information base (MIB). Processes which are used in this information are called as management entities. The TMN provides telecommunication service to various operating system and telecommunication network. • There are many building blocks in TMN.There are two classes of Q interfaces: Q• 3 and QX.

TMN supplies a model of logical layer which defines or suggest the management level for specific functionality. • There are mainly two levels named highest level and lower level.

ReferencesB. G. Evans and K. Baughan. • Visions of 4G, Electronics and Communication Engineering Journal, December 2002.C. Kikkert, (2004). • Digital Communication Systems and their Modulation Techniques. James Cook University, 4th edition.H. Honkasalo, K. Pehkonen, M. T. Niemi, and A. T. Leino, (2002). WCDMA and WLAN for 3G and beyond. • IEEE Wireless Communications. 9(2)P14–18.International Engineering Consortium. • http://www.iec.org/ Lars Ahlin, Jens Zander, (1998). • Principal of Wireless Communications. Studentlitteratur, 1998.T. Ojanpera and R. Prasad (editors), (1998). • Wideband CDMA for Third Generation Mobile Communications. Artech House Publishers.William Stallings, (2003). • Wireless Communications and Networking, Prentice Hall.

Recommended ReadingKevin Laird, Nick Whinnet, and Soodesh Buljore. • A Peak-To-Average Power Reduction Method for Third Generation CDMA Reverse Links, in Proc., IEEE Vehicular Technology Conference, 1999.Esmael H. Dinan and Bijan Jabbari, • Spreading Codes for Direct Sequence CDMA and Wideband CDMA Cellular Networks, IEEE Communications Magazine, vol. 36, P48–54, September 1998.

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Self Assessment

NEL interfaces between the _________ information and TMN infrastructure.1. manageable a. unmanageableb. importantc. desiredd.

Which statement is true?2. Open system interconnect reference model defines the six layers of OSI reference model.a. Open system interconnect reference model defines the three layers of OSI reference model.b. Open system interconnect reference model defines the seven layers of OSI reference model.c. Open system interconnect reference model defines the five layers of OSI reference model.d.

_________ principles are incorporated into telecommunication network to send and receive information and 3. to manage its resources.

TMNa. NMSb. WSc. OSId.

Uses information presented by NML to manage contracted services to existing and potential customer belongs 4. to ________.

SMLa. NMSb. WSc. OSId.

A key point for interaction with service providers and with other administrative domain belongs to ________.5. WSa. SMLb. NMSc. OSId.

What does GDMO stand for?6. Guideline for Definition of Management Object a. Guideline for Developing Managed Object b. Guideline for Definition of Managed Object c. Guideline for Definition of Managed Objectivesd.

________ manages individual NEs and NEs as a group.7. NMLa. NMSb. WSc. OSId.

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________ presents the TMN manageable information in an individual NE.8. NMSa. WSb. OSIc. NELd.

High level planning falls under _________.9. OSIa. NMSb. BMLc. WSd.

Business level agreement falls under _________.10. BMLa. NMSb. WSc. OSId.

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Chapter V

Network Management Tools and Systems

Aim

The aim of this chapter is to:

explain• social network analysis

elucidate SNA as a diagnostic tool •

depict system management lifecycle •

Objectives

Objectives of this chapter are to:

explain the fundamentals of social network analysis•

elaborate social network analysis as a diagnostic tool•

give in short the concept of commercial network management•

Learning outcome

At the end of this chapter, the students will be able to:

understand applications of SNA as diagnostic tool•

recognise the solutions for system management task•

know ab• out network architecture and various kinds network management tools

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5.1 Network Management ToolsNetwork management means monitoring an active communications network in order to diagnose problems and gather statistics for administration and fine tuning. Examples of network management products are IBM’s NetView, HP’s OpenView, Sun’s SunNet Manager and Novell’s NMS. Almost all network management software supports the SNMP network management protocol. Other management protocols are CMIP and DME.

There are mainly three kinds of network management tools are available:

Diagnostic tool:1. used to test connectivity, ascertain that location is reachable.Monitoring tool:2. used to collect events and also initiate the own probes (using diagnostic tools), and recording the output in a schedule fashion.Performance tool:3. used that how network is handling traffic flow.

5.2 Social Network AnalysisSocial network analysis (SNA) is a methodology with increasing applications within the social sciences and has • been applied to areas as diverse as health, psychology, business organisation, and electronic communication. It uses in the field of rural development.The concept of networks is becoming ever more obvious in daily life as people are becoming more connected • to each other and it is increasingly common for people to work as virtual networks without necessarily having to meet in physical spaces. As these networks expand there is a growing awareness of the importance of social networks in all settings, • whether these are virtual networks as used by international companies or the social relationships used by remote communities to identify a new market for their crops.Social network analysis has been developed to understand these relationships and has two main focuses; the • user and the relationships between them in a specific social context. These focuses help to understand how the user’s position in a network influences their access to resources such • as goods, capital and information. This infers that economic activity is linked to social structures, which has led to the concept of social capital.Information is one of the most important resources that flow through networks and so SNA is often applied to • identify both information flows and bottlenecks. In theory, identifying these flows and bottlenecks should help identify improved strategies to encourage different • users to share information based on improving flows in the existing social system rather than seeking to create new ones.As users create links with other users to access resources they form clusters in which users with the best position • are better informed. The users with access to a range of sources of information usually belong to various clusters, which gives them a certain degree of power as they act as intermediaries for those who have fewer contacts and therefore less access to information. It should be pointed out that the flows are not necessarily equitative meaning that hierarchies are formed based • on the position of an actor within the network.Networks do not only provide access to resources but also to other actors who can help to give value to these • resources. This suggests that actors can structure their social networks to maximize their benefits by getting closer to the existing resources and opportunities. While there is still much work to be done to find ways of using SNA as a tool to build social capital, it is hoped • that the first step will be the possibility of at least visualising the relationships among the different actors interacting in a certain setting. It is important to identify how to strengthen these social relationships to create more equitative conditions for • those rural communities not well connected to the networks where resources flow and decisions are made. Nevertheless, it is hoped that this tool will help people to understand how these systems work as well as understand their position within the network.

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5.3 SNA as a Diagnostic Tool Social network studies usually take one of two approaches:•

The first with a closed group, for example, to look at the relationships among people working in an �institution.Second focuses on one person and seeks to understand their ego or the social relationships surrounding �them.

In rural development neither of these approaches is appropriate as it would be too expensive to interview all • of the resources working in a certain zone or on a specific subject. The different sorts of relationships between individual people and institutions also need to be analysed and, in order to fully understand innovation processes, it is necessary to visualise the information flows and exchanges between both levels at the same time.Rural development projects operate within an extremely complex socio-institutional framework where grassroots • organisations, non-governmental organisations, public and private institutions all interact at the local, regional, national or international level. This inherent heterogeneity if further complicated by the tendency of international donor agencies to fund • short or medium-term projects encouraging alliances with various partners which can limit the possibilities for continuity and consolidation of successful experiences.When the social network analysis methodology is applied as a diagnostic tool, it can help address some of the • challenges associated with planning and implementing rural development projects, by showing institutional trends and identifying similar initiatives to avoid duplicating efforts and facilitate the construction of social capital among different actors. Visualising community level and organisational networks can help to understand local relationships by • demonstrating the interactions between different groups and identifying the most influential actors.The maps created by this tool have great potential to provide immediate information about what is happening • on the ground. The visual graphics are able to capture the attention and imagination of rural actors whose literacy levels are sometimes very low, which may act as a disincentive to participate in research projects or read written reports. The maps can help outsiders to identify key actors in the local network, which can be a good guide for deciding • who to involve in a project or at least who to consult during the initial stages in the hope that involving them in planning and implementation will lead to better participation and more rapid appropriation of innovations. The wide variety of actors and number of topics that interlink in the field of rural development should not be • seen as a hindrance for an SNA study, but rather what supports the validity and utility of SNA as a diagnostic tool, to provide quick, visual, and extremely useful results for those working in this discipline.

5.4 System Management Major functionality of system management is to design, test, deploy, and manage clients and server throughout the organisation.

5.4.1 System Management Lifecycle System management is a continuous process of discovering, adaptation and maintenance. This management lifecycle evaluate the current system; modifies the requirements and tests and deploys the new system.

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Manage Evaluate

Deploy

Fig. 5.1 System management life cycle

Evaluate: • This phase of life cycle may take few weeks or months to execute. Once the evaluation is complete, it is time to recommend software hardware additions, replacement, and modification. Deploy: • New sets of hardware, software, and management tools are tested and modified as required. After the final configurations are in place, the deployment phase involves extensive testing of the new solutions in a live environment.Manage: • The management phase begins as soon as deployment is complete and extends throughout the year, overlapping the next iteration of the evaluation and deployment phases. As the cycle progresses, some steps may iterate within the cycle. For example, images may need to be tested repeatedly, and systems may require occasional updates or repairs.

5.5 System Management TaskThe systems management lifecycle is supported by a set of IT tasks that drive the effective management of large deployments while meeting the requirements of the organisation. To control and keep systems up and running, it’s critical to have solutions in place to fulfil each task.

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Help DeskManagement

AssetManagement

Imaging

SoftwareDistribution

Remote ControlUsageManagement

LicenseManagement

Patches and Upgrades System

ManagementTask

Fig. 5.2 System management task

Asset management: • To maintain control, one must keep track of all the hardware and software that the organisation has purchased or acquired. To plan upgrades, one need to know, at a glance, which systems have enough RAM. Asset management refers to the knowledge of what’s on the systems as well as where it’s located.Imaging: • Creating, maintaining, and deploying images is an essential part of systems management. The required number of images depends on many factors, such as portables versus desktops, servers versus clients, basic-use systems versus high-end workstations. It’s also essential to have an imaging process in place, starting with the proper configuration of images and extending to a procedure for deploying them—whether manually or automatically, in person or across a network.Software distribution: • Once you have applied the core system images, you may need to customise them with special applications and settings for different sites. Software distribution refers to the addition of capabilities to baseline images.Remote control: • It’s often necessary to “reach out and touch” your end users—whether they are teachers in a classroom or support desk staff solving a user issue. Remote control capabilities are the main key to interacting with users in these scenarios.Usage management: • How do end users interact with their systems? How do you keep systems in shared environments up and running? And how do you provide a consistent user experience that adheres to organisational policies? Usage management combines technology with acceptable use policy and touches workflow management, which provides a mechanism for users to interact with each other in day-to-day operations.License management: • This task includes tracking software use, controlling access to certain applications, and reporting on application misuse. Through license management, you can help ensure that the software on your organisation’s equipment is legal and is only used by authorized individuals.Patches and upgrades: • Despite your best intentions to deploy the “perfect” image, you need to allow for critical patches and upgrades to current applications on deployed systems.

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Help desk management: • What issues are coming up? What problems are users having, and how can you help them? Help desk operations involve short-term training, trouble ticket management, and reporting on which systems aren’t working properly.

5.6 Solutions for System Management TaskApple is one of the organisations which basically made the solution for system management. It supports the Mac users in organisation, covering most of the task in system lifecycle.

5.6.1 Apple Remote Desktop 3Apple Remote Desktop 3 is an integrated desktop management tool that allows system administrators and instructors to perform tasks within three areas: reporting, managing, and interacting.

Apple Remote Desktop agent can be run on Mac OS X clients and servers to gather system information and enable client-side interactions, and the Apple Remote Desktop administrator to create reports and manage and interact with those systems. In addition, a copy of Apple Remote Desktop can be installed on a system as a task server to act as a central database for reports, package installs, and agent information.

Asset managementUsing the Spotlight technology in Mac OS X, Apple Remote Desktop can perform detailed searches on all your • Mac OS X systems. You can quickly generate comprehensive user histories and application usage reports, as well as hardware and • software inventories about servers, desktop systems, and portable computers.

Software distributionApple Remote Desktop makes it easy to install or copy software across a network of Mac computers, including • remote systems. You can make sure that all systems in your organisation are running the most current version of Mac OS X or running the same applications, fonts, and templates. And with the “Send UNIX command” tool, you can interact with the Apple Software Update Server (SUS) to • send approved updates to client systems without requiring user response.

Remote controlApple Remote Desktop allows you to configure systems, run applications, empty the Trash, log out current • users, set the start-up disk, and lock screens—from anywhere on the network. For complete remote control, you can use Apple Remote Desktop to share, observe, or control any number of • remote Mac or Virtual Network Computing (VNC)–enabled computers.

Usage managementUse Apple Remote Desktop to gather information and generate reports so you can see who’s logging into client • systems and which applications are being run by which users.

Patches and upgradesWith Apple Remote Desktop, you can copy new files, install package (PKG) files, locate and delete old files, • and interact with the Software Update Server to update client systems automatically. The task server can act as a “Store and forward” location for PKG files, even while systems are offline.•

Help desk managementSince you can use Apple Remote Desktop to observe or control remote Mac or VNC enabled computers, it’s • easy to assist and train remote users. Features include easy drag and drop of files, remote copy and paste of text and images, and Curtain Mode for • concealing sensitive information from users.

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5.6.2 Mac OS X ServerMac OS X Server is Apple’s fully compliant UNIX server operating system that includes services and applications designed to support many systems lifecycle tasks.

Imaging and software distributionThe NetBoot service in Mac OS X Server enables multiple Mac systems to boot from a single, server-based disk • image, instead of from their internal hard drives. This allows you to create a standard configuration and use it on all of the desktop systems in a department or classroom—or host multiple images customised for different workgroups. One can even create server configurations and run all of servers from one image. Updating the disk image on • the NetBoot server updates all of these systems automatically the next time they restart. In addition, one can copy a directory server configuration to all clients using the same system image. For • security-conscious organisations, NetBoot permits Mac computers to boot “diskless”—without having to read from or write to the computer’s local drive. The NetInstall service provides an easy method for standardised deployment, giving you control over the • software installed in your organisations. By creating server-based disk images with custom configurations, you can upgrade or restore Mac clients anywhere on your network—saving time and eliminating the expense of distributing software on DVD or FireWire drives. The System Image Utility included in Mac OS X Server version 10.5 leverages the power of Automator, giving • you an intuitive interface for creating NetBoot and NetInstall disk images. Choose from a preloaded library of actions that allow you to specify settings, additional software packages, and installation procedures—and then save them as a workflow that builds the installation image.

Usage managementWorkgroup manager is a powerful application for centralising client management, defining administrative • policies across users and computers, and facilitating classroom and workgroup collaboration. Using Workgroup Manager, one can grant access to network services, establish password policies, and create standardised desktop environments. By setting system preferences on a per-user, per-group, or per-computer basis, you can provide a level of flexibility • appropriate to your administrative needs. For example, you can create custom environments—with appropriate applications, settings, and permissions—for a workgroup or classroom. When users log in, predefined group applications launch automatically, and shared network resources are mounted on the desktop. The same functionality can be used to restrict operations: For example, one can set preferences that disable • media burning or restrict outgoing email traffic or that require authentication for access to specific devices or printers. The preferences and policies you define in Workgroup Manager can be stored in any LDAP directory server—including Apple’s Open Directory and proprietary systems such as Microsoft’s Active Directory.

5.7 Enterprise Management SystemElement Management Systems (EMSs) are NMSs that are designed to manage a particular device, often • implemented by the device manufacturer. EM Systems as NMSs capable of managing devices, independent of vendors and protocols, in IP-based enterprise networks. This method is in contrast to NMS for Carrier Networks, which have different architectures and are not covered • in this article. EM Systems are software solutions that allow systems administrators to manage a vast set of heterogeneous devices in their data centres. In the last two decades, we have witnessed three major phases of evolution in enterprise networking technology. The • first phase moved from a centralised mainframe and dumb terminal architecture to a distributed architecture. A distributed architecture was composed of islands of departmental local area networks (LANs). The second • phase involved linking all these disparate departmental LANs and creating an enterprise-wide network. This configuration had two major implications.

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First, the complexity of managing the enterprise-wide network increased profoundly. Second, a heterogeneous • environment emerged from this integrated architecture. The third phase arose as a result of Web-based enterprise services. This changed the enterprise traffic patterns and increased the dependency on mission-critical enterprise services and infrastructures.

5.8 Network Architecture The network architecture describes how the EM Systems is deployed. There are several models that can be • employed to organise how the managers are organised. Models can be a single central manager, hierarchical managers, distributed peer managers, etc. Network architecture also includes the management protocols that are used to communicate information about • the management resource between the managers and agents.EM Systems can be organised in a variety of architectures, and can communicate management information • using one of two standard network management protocols:

SNMP for IP-based networks �Common Information Model Protocol (CMIP) for Open Systems Interconnection (OSI)-based networks �

Due to the industry wide acceptance of SNMP, CMIP is not discussed here. Figure 5.3 (a) describes an overview of the main types of ES System architectures. The choice of architecture • has a direct impact on scalability, availability, performance, and security.Figure 5.3 (b) describes a centralised architecture, where a single NMS manages all the devices on an enterprise • network. The single NMS has limited performance and scalability, in terms of network and computing capabilities. Figure 5.3 (c) describes a highly distributed system, where any management server can communicate with any • managed device. This architecture offers a highly available solution. If one management system fails, there is a backup system to assume responsibility of that domain. This approach also permits specialisation of services.

NMS consoleand server

Manageddevice

Manageddevice

Manageddevice

Manageddevice

Fig. 5.3 (a) Centralised network architecture

Fig. 5.3 (b) Hierarchical network architecture

NMS console

NMS server

NMS server NMS server

Manageddevice

Manageddevice

Manageddevice

Manageddevice

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Fig. 5.3 (c) Distributed network architecture

5.9 Commercial Network Management SystemA commercial network management tool is mostly used in (large) corporations. It can log the network traffic • passively (sniffing) or examine the logs of proxies, etc. Nothing is installed on the individual computers, the software runs on a central server. They can only log items that pass through the network, but not local items such as the entered passwords, • keystrokes, or screenshots. The commercial network tools provide various features like graphical network maps, scalability to manage • thousands of servers or network, automation of performance information etc. some of the major commercial products which provides the extensive systems and network management functionality are like Hewlett-Packard’s (HP’s) OpenView Network Node Manager and OpenView ManageX, BMC Software’s PATROL, NetIQ’s AppManager Suite, IBM’s Tivoli, and Computer Associates’ (CA’s) Unicenter TNG.

NMS console NMS console

Manageddevice

Manageddevice

Manageddevice

Manageddevice

NMS serverNMS server

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SummaryMonitoring an active communications network in order to diagnose problems and gather statistics for • administration and fine tuning. Examples of network management products are IBM’s NetView, HP’s OpenView, Sun’s SunNet Manager and Novell’s NMS. Almost all network management software supports the SNMP network management protocol. Other management protocols are CMIP and DME. Social network analysis (SNA) is a methodology with increasing applications within the social sciences and has • been applied to areas as diverse as health, psychology, business organisation, and electronic communication. It is used in the field of rural development.System management is a continuous process of discover, adaptation and maintenance. This management lifecycle • evaluates the current system; modify the requirements and testing and deploying the new system.Apple is one of the organisations which basically made the solution for System Management. It supports the • Mac users in organisation and covering most of the task in system lifecycle. The network architecture describes how the EM Systems is deployed. There are several models that can be • employed to organise how the managers are organised. Models can be a single central manager, hierarchical managers, distributed peer managers, etc. The commercial network tools provide various features like graphical network maps, scalability to manage • thousands of servers or network, automation of performance information etc. Some of the major commercial products which provides the extensive systems and network management functionality.

ReferencesEnterprise Management Systems Part I: Architectures and Standards.• Deepak Kakadia, Sun Microsystems, Inc., Dr. Tony G. Thomas, AdventNet, Inc., Dr. Sridhar Vembu, Adventnet, Inc., Jay Ramasamy, AdventNet, Inc., Sun BluePrintsTM OnLine - April 2002. Last accessed 5th March 2011.Enterprise System Management.• (2001). Daniel J. Oberst. Available at: <http://net.educause.edu/ir/library/pdf/ERM0127.pdf> Last accessed 5th March 2011.Louise Clark, (2006). • Network Mapping as a Diagnostic Tool Manual, CIAT 2006. Available at: <http://revista-redes.rediris.es/webredes/talleres/networkmapping_LC06.pdf> Last accessed 28th February 2011. Network Management and Monitoring Overview.• (2009). Nadi, Fiji. Available at: <http://www.pacnog.org/pacnog6/presentations/linux-network/network-management.pdf> Last accessed 5th March 2011.Solution for System Management. October 2008. Available at: <http://images.apple.com/education/docs/Apple-• SolutionsSystemMgmt.pdf> Last accessed 5th March 2011.Solutions for Systems Management, White Paper, October 2008. Available at: <http://images.apple.com/• education/docs/Apple-SolutionsSystemMgmt.pdf> Last accessed 5th March 2011.Standardise System Management. (2009). Available at: <http://www.altiris.com/upload/wp-standardized_• systems_management_v1.3.pdf> Last accessed 5th March 2011.System Management Bus Specification. Available at: <http://smbus.org/specs/smbus20.pdf> Last accessed 5• th March 2011.

Recommended ReadingMani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.Mark Burgess, (2004). • Principles of Network and System Administration. Wiley Dreamtech. 634 pages.

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Self Assessment

__________ is often applied to identify both information flows and bottlenecks.1. SNAa. NMSb. SNMPc. MIBd.

___________ is one of the most important resources that flow through networks.2. Databasea. Bandwidthb. Informationc. Datad.

Who developed product named Tivoli?3. Microsofta. Appleb. HPc. IBMd.

The network architecture describes how the __________ is deployed.4. SNMPa. EM Systems b. NMSc. MIBd.

Which statement is false?5. NMSs are EMSs that are designed to manage a particular device.a. A distributed architecture was composed of islands of departmental LANs. b. EM Systems are software solutions that allow systems administrators to manage a vast set of heterogeneous c. devices in their data centres. The last two decades have witnessed three major phases of evolution in enterprise networking technology.d.

A commercial network management tool is mostly used in ________ corporations.6. governmenta. privateb. largec. smalld.

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Data communication concept is based on the __________between two computers and exchange of information 7. between them.

communicationa. interactionb. interconnectionc. transparencyd.

OpenView product belongs to which company?8. HPa. Novellb. IBMc. Oracled.

Data transmission can be termed as _________.9. movement of dataa. piling of datab. gathering of datac. collection of datad.

Now days the telephone network is referred to as ____________.10. PSTNa. NMSb. NOCc. TMNd.

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Chapter VI

Universal Mobile Telecommunications System

Aim

The aim of this chapter is to:

emphasise on the basics of UMTS•

describe WCDMA air interface and UMTS packet data in detail•

illustrate the system architecture of UMTS•

Objectives

The objectives of this chapter are to:

enable the students to learn the fundamental concept of the Universal Mobile Telecommunications System•

enrich them with the duplex method of Wideband Code Division Multiple Access•

explain the analysis of spectrum allocation and migration path of UMTS•

learn the establishment of basic speech call of UMTS in detail•

Learning outcome

At the end of this chapter, the students will be able to:

define the literary term UMTS and explain basics of UMTS•

enlist the primary plot details of WCDMA air interface•

und• erstand the system architecture, migration path, spectrum allocation and packet data of UMTS

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6.1 IntroductionUMTS (Universal Mobile Telecommunications System) represents an evolution in terms of capacity, data speeds and new service capabilities from second generation mobile networks. Japanese operator NTT DOCOMO launched the world’s first commercial WCDMA network in 2001. Today, more than 60 3G/UMTS networks using WCDMA technology are operating commercially in 25 countries, supported by a choice of over 100 terminal designs from Asian, European and US manufacturers. 3G/UMTS specified and implemented as an end-to-end mobile system, and have the following additional benefits:

automatic international roaming plus integral security and billing functions, allowing operators to migrate from • 2G to 3G while retaining many of their existing back-office systemsoffering increased capacity and speed at lower incremental cost compared with second generation mobile • systems3G/UMTS gives operators the flexibility to introduce new multimedia services to business users and consumers • while providing an enhanced user experienceprovides the opportunity for operators to build on the brand-based relationships they already enjoy with their • customersdrives new revenue opportunities by encouraging additional traffic, stimulating new usage patterns and • strengthening customer loyalty

6.2 UMTS BasicsAir Interfaces

UMTS provides several different terrestrial • air interfaces, called UMTS Terrestrial Radio Access (UTRA).All air interface options are part of • ITU’s IMT-2000. Non-terrestrial radio access networks are currently under research.

W-CDMAIt uses the • DS-CDMA channel access method with a pair of 5 MHz channels.The competing • CDMA2000 system uses one or more arbitrary 1.25 MHz channels for each direction of communication.

UTRA-TDD HCRThe • UMTS-TDD’s air interfaces that use the TD-CDMA channel access technique, are standardised as UTRA-TDD HCR, which uses increments of 5 MHz of spectrum.Each slice is divided into 10ms frames containing fifteen time slots (1500 per second).•

TD-SCDMA (UTRA-TDD 1.28 Mbps Low Chip Rate):The TD-SCDMA uses the • TDMA channel access method combined with an adaptive synchronous CDMA component on 1.6 MHz slices of spectrum.This allows deployment in even tighter frequency bands than TD-CDMA.•

Radio access networkUMTS also specifies the UMTS Terrestrial Radio Access Network (UTRAN).• The UTRAN is composed of multiple base stations, possibly using different terrestrial air interface standards • and frequency bands.

Core networkUMTS uses the same core network standard as GSM/EDGE with Mobile Application Part.• This allows a simple migration for existing GSM operators.•

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However, the migration path to UMTS is still costly, while much of the core infrastructure is shared with GSM, • the cost of obtaining new spectrum licenses and overlaying UMTS at existing towers is high.

6.3 UMTS ServicesUMTS specifications define four service classes, where the services within a given class have a common set of characteristics. The service classes are as follows:

Conversational• is characterised by low delay tolerance, low jitter (delay variation) and low error tolerance �the data rate requirement may be high or low, but is generally symmetrical �the data rate in one direction will be similar to that in the other direction �

Voice• is highly delay-sensitive �is a typical conversational application, the one that does not require very high data rates �video conferencing is also a conversational application �has similar delay requirements to voice, but is less error-tolerant and generally requires a higher data rate �

Interactive• consists of typically request/response-type transactions �interactive traffic is characterised by low tolerance for errors, but with a larger tolerance for delays compared �to conversational servicesjitter (delay variation) is not a major impediment to interactive services, provided that the overall delay �does not become excessiveinteractive services may require low or high data rates depending on the service in question, but the data �rate is generally significant only in one direction at a time

Streaming• concerns one-way services, using low- to high-bit rates �have a low-error tolerance, but generally have a high tolerance for delay and jitter. This is because receiving �application usually buffers data so that it can be played to the user in a synchronised mannerstreaming audio and streaming video are typical streaming applications �

Background• characterised by little, if any, delay constraint �Example - server-to-server e-mail delivery (as opposed to user retrieval of e-mail), SMS, and performance/ �measurement reportingapplications require error-free delivery �

6.4 UMTS System ArchitectureThe basic architecture of the UMTS as shown below is modelled on the lines on the GSM/GPRS network • architecture. Hence, there are many similarities between the two architectures but, the actual protocol residing in their entities are quite different. In UMTS Access network, WCDMA air interface is used due to which there is a significant change, residing in • the protocol in the UMTS User equipment and the Access network.

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Fig. 6.1 UMTS system architecture

6.5 Migration Path of UMTSThe radio access for UMTS is known as Universal Terrestrial Radio Access (UTRA). This is a WCDMA-based • radio solution, which includes both FDD and TDD modes.The radio access network (RAN) is known as UTRAN. It takes more than an air interface or an access network • to make a complete system. However, the core network must also be considered.Because of the widespread deployment and success of Global System for Mobile communications (GSM), it is • appropriate to base the UMTS core network upon an evolution of the GSM core network.Here, the primary focus will be on the FDD mode of operation, with less emphasis on TDD with respect to the • description of UMTS technology with the WCDMA air interface.

6.6 UMTS Spectrum AllocationThe 2100 MHz UMTS spectrum allocated in Europe is already used in North America. The 1900 MHz range • is used for 2G (PCS) services, 2100 MHz range is used for satellite communications and regulators have freed up some of the 2100 MHz range for 3G services, together with the 1700 MHz for the uplink.UMTS operators in North America who want to implement a European style 2100/1900 MHz system will have • to share spectrum with existing 2G services in the 1900 MHz band.Carriers in South America are now rolling out 850 MHz networks.• AT&T Wireless launched UMTS services in the United States by the end of 2004 strictly using the existing • 1900 MHz spectrum allocated for 2G PCS services. Cingular acquired AT&T Wireless in 2004 and has since then launched UMTS in selected cities of the US. Cingular was renamed to AT&T and has rolled out a few other cities with a UMTS network at 850 MHz to • enhance its existing UMTS network at 1900 MHz and now offers subscribers a number of UMTS 850/1900 phones.In 2008, Australian Telco Telstra replaced its existing CDMA network with a national 3G network, branded as • NextG, operating in the 850 MHz band. Telstra, also co-owned by Hutchison 3G Australia, currently provides UMTS service on this network, and also on the 2100 MHz UMTS network, through a co-ownership of the owning and administrating company 3GIS.

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Optus is currently rolling out a 3G network operating on the 2100 MHz band in cities and most large towns, • and the 900 MHz band in regional areas.In India, BSNL has started its 3G services since October 2009 beginning with the larger cities and then expanding • over to smaller cities. The 850 MHz and 900 MHz bands provide greater coverage compared to equivalent 1700/1900/2100 MHz networks are best suited to regional areas where greater distances separate subscriber and base station.

6.7 The UMTS Air InterfaceThe UMTS air interface is a Direct-Sequence CDMA (DS-CDMA) system.Given that, this is a radical departure from the TDMA techniques of GSM, GPRS, and EDGE, it is worth briefly describing the concepts involved.

6.7.1 WCDMA Basics

DS-CDMA means that user data is spread over a much wider bandwidth through multiplication by a sequence • of pseudo-random bits called chips.Figure 6.2 provides a conceptual depiction of this spreading.• One can see that the user data, at a relatively low rate compared to the rate of the spreading code, is spread over • a signal that has a higher bit rate.We can also see that the signal that is transmitted has pseudo-random characteristics.• When transmitted over a radio interface, the spread signal looks like noise.• If multiple users transmit simultaneously on the same frequency, then the stream of data from each user needs • to be spread according to a different pseudo-random sequence. In other words, each user data stream needs to be spread according to a different spreading code. At the receiving end, the stream of data from a given user is recovered by dispreading the set of received signals with the appropriate spreading code.Of course, what is being dispread is the complete set of signals received from all users that are transmitting.• Example, suppose there are two users (A and B) that are transmitting on the same frequency, but with two • different spreading codes.

If, at the receiving end, the received signal is dispread with the spreading code applicable to user A, then �the original data stream from user A is recovered.The data stream that is recovered does have some noise created by the fact that the received signal also �contains user data from user B. The noise, however, is small.Similarly, if the received signal is dispread according the spreading code used by user B, then the original �data stream from user B is recovered, with a little noise generated by the presence of user as data within the spread signal.

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Fig. 6.2 DS-CDMA basic concept

The WCDMA air interface of UMTS (hereafter simply WCDMA) has a nominal bandwidth of 5 MHz. �While 5 MHz is the nominal carrier spacing, it is possible to have a carrier spacing of 4.4 MHz to 5 MHz in steps of 200 kHz. This enables spacing that might be needed to avoid interference, particularly if the next 5 MHz block is �allocated to another carrier.

6.7.1.1 Calculating Spreading Factor

The chip rate in WCDMA is 3.84 x10 chips/second (3.84 Mbps). In theory, for a speech service at 12.2 Kbps • (and, for now, assuming no extra band width for error correction), the spreading factor would be 3.84x106 /12.2x103=314.75. This would equate to a processing gain of 25 dB.In reality, however, WCDMA does include extra coding for error correction. Consequently, a spreading factor • as high as 314.75 is not supported, at least not in the uplink. The supported uplink spreading factors are 4, 8, 16, 32, 64, 128, and 256.The highest spreading factor (256) is used mostly by the various control channels. Some control channels can • also use lower spreading factors, while user services generally use lower spreading factors.

Table 6.1 provides a summary of the spreading factors and the corresponding data rates on the uplink.Spreading

FactorGross Data Rate

(kbps)User data rate (kbps) (assuming half–rate

coding error correction)256 15 7.5128 30 1564 60 3032 120 6016 240 1208 480 2404 960 480

Table 6.1 Spreading factors and the corresponding data rates on the uplink

Transmitting end

User DataStream

Spreading Code

Spreading Signal — user data multiplied by spreading code

Receiving end

Received Spread Signal

Spread Code

user data bit duration

chip duration

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From table 6.1At first glance, it appears that the lowest spreading factor (4) provides a gross rate of only 960 Kbps and a • usable rate of only 480 Kbps.This does not meet the requirements of IMT-2000, which states that a user should be able to achieve speeds of • 2 Mbps.In order to meet that requirement, UMTS supports the capability for a given user to transmit up to six simultaneous • data channels.Thus, if a user wants to transmit user data at a user rate greater than 480 Kbps, then multiple channels are used, • each with a spreading factor of four.With six parallel channels, each at a spreading factor of four, a single user can obtain speeds of over 2 Mbps.• In the downlink, the same spreading factors are available, with a spreading factor of 512 also possible.• One difference between the uplink and downlink, however, is the number of bits per symbol.• As will be described later, Universal Mobile Telecommunications Service (UMTS), the uplink effectively uses • one bit per user symbol, while the downlink effectively uses two bits per user symbol.Consequently, for a given spreading factor, the user bit rate in the downlink is greater than the corresponding • bit rate in the uplink.The user rate in the downlink is not quite twice that in the uplink, however, due to differences in the way that • control channels and traffic channels are multiplexed on the air interface.Table 6.2 provides a summary of the spreading factors and the corresponding data rates on the downlink.•

Spreading Factor

Gross air interface bit rate

(kbps)

User data rate (kbps) (including coding for

error correction)

Approximate net user data rate (kbps) (assuming half

rate coding)512 15 3-6 1-3256 30 12-36 6-12128 60 42-512 21-2564 120 90 4532 240 210 10516 480 432 2168 960 912 4564 1920 1872 936

Table 6.2 Downlink spreading factors and data rates

6.7.2 The WCDMA Air Interface

The WCDMA air interface, referred also as UMTS terrestrial radio access (UTRA), is developed by the third-• generation partnership project (3GPP).WCDMA has two modes characterised by the duplex method:•

FDD (frequency division duplex) – for operating with paired bands �TDD (time division duplex) – for operating with unpaired bands �

For the channel coding, three options are supported:• convolutional coding �turbo coding �no channel coding �

Channel coding selection is indicated by upper layers and bit interleaving is used to randomise transmission • errors.The carrier spacing has a raster of 200 kHz and can vary from 4.2 to 5.4 MHz.•

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Different carrier spacing’s can be used to obtain suitable adjacent channel protections depending on the • interference scenario.For example, fig. 6.3 shows the operator bandwidth of 15 MHz with three cell layers.•

Larger carrier spacing can be applied between operators than within one operator’s band in order to avoid �inter-operator interference.Inter-frequency measurements and handovers are supported by WCDMA to utilise several cell layers and �carriers.

Fig. 6.3 Frequency utilisation with WCDMA

6.7.2.1 Uplink Spreading, Scrambling and Modulation

To uplink the data, DPDCH (Dedicated Physical Data Channel) and the DPCCH (Dedicated Physical Control • Channel) both use Binary Phase Shift Keying (BPSK).Modulation of DPCCH is mapped to the Q-channel on the other hand modulation of DPCCH is mapped to the • I-channel.Moreover, I-channel and Q-channel both maps subsequently of the added DPDCHs.• Spreading modulation is utilised before shaping of pulse and modulation of data. It is used to uplink of data and • dual channel QPSK (Quadrature Phase Shift Keying).Spreading modulation has two kinds of operations:•

In the first spreading modulation, data stream is expanded to various number of chips received from the �spreading factor. This maximizes the utilisation of bandwidth of the signal.The second method is scrambling. To spread signal complex valued scrambling is utilised. �

The spreading and modulation technique of an uplink subscriber is described below.

4.2-5.0 MHz 4.2-5.0 MHz

3 cell layers

Power

Another UMTSoperator

Another UMTSoperator

5.0-5.4 Mhz 5.0-5.4 Mhz

Frequency

Operator band 15 Mhz

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Fig. 6.4 Uplink spreading, scrambling and modulation

From fig. 6.4,The uplink subscriber has a DPDCH and a DPCCH.• Here bipolar data streams on I and Q extensions are separately multiplied by various channelisation codes. This • is called Orthogonal Variable Spreading Factor (OVSF) codes.Complex scrambling code is achieved by multiplication of the signal we get.• It’s the code of particular signature of a base station.• The scrambled signal is transformed to pulse shaped.• Pulse shape is achieved by Square-Root Raised Cosine filters with roll-off factor of 0.22.• This is the technique of a complex scrambling code with spreading modulation as detailed before is usually • called as Hybrid Phase Shift Keying (HPSK).Peak-to-average power of a mobile station is minimized by HPSK by producing the complex scrambling.• Control channel always has the highest value of spreading factor set to 256.• This technique progresses the noise resistance to the control channel because of the highest potential processing • gain.

6.7.2.2 Downlink Spreading, Scrambling and Modulation

Quaternary Phase Shift Keying (QPSK) is deployed to downlink of data modulation. Each duo is two bits serial-• to-parallel transformed and drafted to I and Q subdivision correspondingly.The data in I and Q subdivisions are expanded to the chip rate by the same channelisation code.• Scrambling of the spread code is done by a cell specific scrambling code.• Figure 6.5 pictures the spreading and modulation for a downlink subscriber.• Downlink subscriber has both DPDCH and DPCCH. Further, DPDCHs are QPSK modulated and spread with • various channelisation codes.There are some differences in between of downlink and uplink of spreading and modulation which are as • follows:

Downlink uses QPSK data modulation technique whereas uplink uses BPSK technique. �Data rates in downlink I and Q-channels are similar on the other hand data rates of uplink I and Q-channels �could be various.If we compare scrambling code in the downlink, it is cell specified. On the other hand for the uplink, mobile �station mentions the scrambling code.

Channelazation Code (CD)Cos (00ct)

Sin (00ct)

p(t)

p(t)

Channelazation Code (Cc)

Control (DPCCH)

jData (DPCCH)

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Fig. 6.5 Downlink spreading, scrambling and modulation

6.7.3 WCDMA Air-Interface Protocol Architecture

Figure 6.6 mentioned below shows the air interface protocol architecture.• The protocol architecture is similar to the current ITU-R protocol architecture, ITU-R M.1035. The air interface • is layered into three protocol layers:

The physical layer (layer 1, L1) �The data link layer (layer 2, L2) �Network layer (layer 3, L3) �

The physical layer interfaces the medium access control (MAC), sub-layer of the data link layer and the radio • resource control (RRC) layer of network layer.The physical layer offers different transport channels to MAC. A transport channel is characterised by how the • information is transferred over the radio interface.Transport channels are channel coded and then mapped to the physical channels specified in the physical • layer.MAC offers different logical channels to the radio link control (RLC) sub-layer of layer 2. A logical channel is • characterised by the type of information transferred.

Fig. 6.6 Air interface protocol architecture

Cos (00ct)

Sin (00ct)

p(t)

p(t)j

(DPCCH)Channelization Code (Ccb)

Scrambling Code (Csc)

Serialto

Parallel(DPCCH)

RCC

RLC RLC

MAC

RLC RLCRLC RLC

RLC

L3

BMC

PCDCPCDC

L2/PDCP

Control

L2/BMC

L2/RLC

physical layer

L2/MAC

L1

Logicalchannels

Transportchannels

RLC

Con

trol

Con

trol

Con

trol

Con

trol

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Layer 2 is split into sub-layers: MAC, RLC, packet data convergence protocol (PDCP) and broadcast/multicast • control (BMC).Layer 3 and RLC are divided into control and user planes. PDCP and BMC exist in the user plane only. In the • control plane, layer 3 is partitioned into sub-layers where the lowest sub-layer, denoted as RRC, interfaces with layer 2. The RLC sub-layer provides ARQ functionality closely coupled with the radio transmission technique used.

6.7.4 WCDMA Channel TypesThe MAC layer provides data transfer services on logical channels. A set of logical channel types is defined for different kinds of data transfer services as offered by MAC.

6.7.4.1 Logical ChannelsEach logical channel type is defined by the type of information that is transferred. Logical channels are classified into two groups:

Control channels for the transfer of control plane information (Table 6.3).• Traffic channels for the transfer of user plane information (Table 6.4).•

Fig. 6.7 Logical channel structure

Control Channel (CCH)

Broadcast Control Channel (BCH)

Paging Control Channel (PCH)

Dedicated Control Channel (DCH)

Common Control Channel (CCCH)

Dedicated Traffic Channel (DTCH)

Common Traffic Channel (CTCH)

Shared Channel Control Channel (SCHCCH)

ODMA Dedicated Control Channel (ODCCH)

ODMA Common Control Channel (OCCCH)

ODMA Dedicated Traffic Channel (ODTCH)

Traffic Channel (TCH)

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Broadcast control channel (BCCH) Downlink channel for broadcasting system control information.

Paging control channel (PCCH)

Downlink channel that transfers paging information and is used when:Network does not know the location cell of the mobile stationThe mobile station is in the cell connected state (utilising sleep mode procedures)

Common control channel (CCCH)

Bidirectional channel that transfer control information between network and mobile stations. This channel is used:

By the mobile stations having no RRC connection with the networkBy the mobile stations using common transport channels when accessing a new cell after cell reselection

Dedicated control channel (DCCH)

Point-to-point bidirectional channel that transmits dedicated control information between a mobile station and the network. This channel is established through RRC connection setup procedure.

ODMA common control channel(OCCCH)

Bidirectional channel for transmitting control information between mobile stations.

ODMA dedicated control channel (ODCCH)

Point-to-point bidirectional channel that transmits dedicated control information between mobile stations. This channel is established through RRC connection setup procedure.

Table 6.3 Logical control channels

Dedicated traffic channel (DTCH)Point-to-point channel, dedicated to one mobile station, for the transfer of user information. A DTCH can exist in both uplink and downlink.

ODMA dedicated traffic channel (ODTCH)

Point-to-point channel, dedicated to one mobile station, for the transfer of user information between mobile stations. An ODTCH exists in relay link. A point-to-multipoint unidirectional channel for transfer of dedicated user information for all or a group of specified mobile stations.

Table 6.4 Traffic channels

6.7.4.2 Transport ChannelsA transport channel is defined by how and with what characteristics data is transferred over the air interface. There exist two types of transport channels:

Dedicated channels• Common channels, listed in Table 6.5•

There is one dedicated transport channel, the dedicated channel (DCH), which is a downlink or uplink transport channel. The DCH is transmitted over the entire cell or over only a part of the cell using beam-forming antennas. The DCH is characterised by the possibility of fast rate change (every 10 ms), fast power control, and inherent addressing of mobile stations.

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Broadcast channel (BCH)Downlink transport channel that is used to broadcast system- and cell-specific information. The BCH is always transmitted over the entire cell with a low fixed bit rate.

Forward access channel (FACH)

Downlink transport channel. The FACH is transmitted over the entire cell or over only a part of the cell using beam-forming antennas. The FACH uses slow power control.

Paging channel (PCH)

Downlink transport channel. The PCH is always transmitted over the entire cell. The transmission of the PCH is associated with the transmission of a physical layer signal, the paging indicator, to support efficient sleep mode procedures.

Random access channel (RACH)

Uplink transport channel. The RACH is always received from the entire cell. The RACH is characterised by a limited size data field, a collision risk and by the use of open loop power control.

Common packet channel (CPCH)

Uplink transport channel. The CPCH is a contention-based random access channel used for transmission of bursty data traffic. CPCH is associated with a dedicated channel on the downlink, which provides power control for the uplink CPCH.

Downlink shared channel (DSCH)

Downlink transport channel shared by several mobile stations The DSCH is associated with a DCH.

Table 6.5 Common transport channels

Mapping between logical channels and transport channelsFigure 6.8 shows the mapping between logical and transport channels. The following connections exist:

BCCH is connected to BCH and may also be connected to FACH.• PCCH is connected to PCH.• CCCH is connected to RACH and FACH.• SHCCH is connected to RACH and USCH/FACH and DSCH.• DTCH can be connected to either RACH & FACH to RACH & DSCH, to DCH and DSCH, to a DCH, a CPCH • (FDD only).CTCH is connected to FACH.• DCCH can be connected to either RACH & FACH, to RACH & DSCH, to DCH and DSCH, to a DCH, a CPCH • to FAUSCH, CPCH.

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Fig. 6.8 Mapping between logical and transport channels

6.7.4.3 Physical Channels

The transport channels are channel coded and matched to the data rate offered by• physical channels. Thereafter, the transport channels are mapped on the physical channels.Physical channels consist of radio frames and time slots.• The length of a radio• frame is 10 ms and one frame consists of 15 time slots.A time slot is a unit, which• consists of fields containing bits.The number of bits per time slot depends on the• physical channel. Depending on the symbol rate of the physical channel, the configuration of radio frames or time slots varies. The basic physical resource is the code/frequency plane.

Uplink physical channelsThere are two uplink dedicated physical and two common physical channels:•

The uplink dedicated physical data channel (uplink DPDCH) and the uplink dedicated physical control �channel (uplink DPCCH)The physical random access channel (PRACH) and physical common packet channel (PCPCH) �

The uplink DPDCH is used to carry dedicated data generated at layer 2 and above (i.e., the dedicated transport • channel (DCH)).There may be zero, one, or several uplink DPDCHs on each layer 1 connection.• The uplink DPCCH is used to carry control information generated at layer 1.• Control information consists of known pilot bits to support channel estimation for coherent detection, transmit • power-control (TPC) commands, feedback information (FBI), and an optional transport-format combination indicator (TFCI).The transport-format combination indicator informs the receiver about the instantaneous parameters of the • different transport channels multiplexed on the uplink DPDCH, and corresponds to the data transmitted in the same frame. For each layer 1 connection there is only one uplink DPCCH.Figure 6.9 shows the principle frame structure of the uplink dedicated physical channels.• Each frame of length 10 ms is split into 15 slots, each of length Tslot = 2560 chips, corresponding to one power-• control period.The parameter k in fig. 6.9 determines the number of bits per uplink DPDCH/DPCCH slot.• It is related to the spreading factor (SF) of the physical channel as SF = 256/2k. The DPDCH spreading factor • may thus range from 256 down to 4.

BCCH

PCCH

CCCH

SHCCH

DTCH

CTCH

DCCH

BCH

FACH

PCH

RACH

CPCH

DSCH

DCH

Logical channels Transport channels

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An uplink DPDCH and uplink DPCCH on the same layer 1 connection generally are of different rates and thus • have different spreading factors.Multiple parallel variable rate services (dedicated logical traffic and control channels) can be time multiplexed • within each DPDCH frame.The overall DPDCH bit rate is variable on a frame-by-frame basis.• In most cases, only one DPDCH is allocated per connection, and services are jointly interleaved sharing the • same DPDCH.Multiple DPDCHs can also be allocated, however.• When multicode transmission is used, several parallel DPDCHs are transmitted using different channelisation • codes.There is only one DPCCH per connection.•

Fig. 6.9 Frame structure for uplink DPDCH/DPCCH

The PRACH is used to carry the RACH.• The random-access transmission is based on a slotted ALOHA approach with fast acquisition indication.• The mobile station can start the transmission at a number of well-defined time-offsets, denoted access slots.• There are 15 access slots per two frames and they are spaced 5120 chips apart.• Figure 6.10 shows the access slot numbers and their spacing to each other. Information on what access slots are • available in the current cell is given by higher layers.The structure of the random-access transmission is shown in Figure 6.11.• The random-access transmission consists of one or several preambles of length 4096 chips and a message of • length 10 or 20 ms.The mobile station indicates the length of the message part to the network by using specific signatures.• The preamble part of the random-access burst consists of 256 repetitions of a signature. There are a total of 16 • different signatures, based on the Hadamard code set of length 16.Figure 6.12 shows the structure of the random-access message part radio frame.• The 10 ms message part radio frame is split into 15 slots, each of length Tslot = 2560 chips. Each slot • consists of two parts, a data part that carries layer 2 information and a control part that carries layer 1 control information.The data and control parts are transmitted in parallel. A 20-ms-long message part consists of two consecutive • message part radio frames.

DPDC

DPCC Pilot Npilot bits

Data Ndata bits

Slot #0 Slot #1 Slot #i Slot #14

1 radio frame: T1 = 10 ms

TFCI NIFCI bits

FBI NFBI bits

TPC NIFC bits

Tslot = 2560 chips, 10x2k bits (K=0. .6)

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The data part consists of 10x2k bits, where k= 0, 1, 2, 3. This corresponds to a spreading factor of 256, 128, 64, • and 32, respectively, for the message data part.The control part consists of eight known pilot bits to support channel estimation for coherent detection and two • TFCI bits. This corresponds to a spreading factor of 256 for the message control part.The PCPCH is used to carry the CPCH transport channel. The CPCH transmission is based on DSMA-CD • approach with fast acquisition indication.The mobile station can start transmission at a number of well-defined time-offsets, relative to the frame boundary • of the received BCH of the current cell.The CPCH random-access transmission consists of one or several access preambles of length 4096 chips, one • collision detection preamble (CD-P) of length 4096 chips, a DPCCH power control preamble (PC-P) (which is either 0 slots or 8 slots in length), and a message of variable length Nx10 ms.

Fig. 6.10 RACH access slot numbers and their spacing

Fig. 6.11 Structure of the random-access transmission

Radio frame: 10 ms Radio frame: 10 ms

5120 chips

Random access transmission

Random access transmission

Random access transmission

Random access transmission

access sbt #0

access sbt #1

access sbt #7

access sbt #8

access sbt #14

#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14

Preamble

Preamble

Preamble Preamble Message part

10 ms (one radio frame)

20 ms (two radio frames)

Message part

4096 chips

4096 chips

Preamble Preamble

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Fig. 6.12 Structure of the random-access message part radio frame

Fig. 6.13 Structure of the CPCH random-access transmission

Downlink physical channelsThere is one downlink dedicated physical channel, one shared and five common control channels:

Downlink dedicated physical channel (DPCH) �Physical downlink shared channel (DSCH) �Primary and secondary common pilot channels (CPICH) �Primary and secondary common control physical channels (CCPCH) �Synchronisation channel (SCH) �

Fig. 6.14 Frame structure for downlink DPCH

Figure 6.14 shows the frame structure of the DPCH. On the DPCH, the dedicated transport channel is transmitted •

Source (Sender) Medium Receiver

(Sink)

P0P1

P1

4096 chips

Message part

N × 10 msec0 or 8 slots

DPCCH

DPDCHCollision resolution preamble

Access preamble

P1

DPDCH DPCCH DPDCH DPCCH

Data 1 NData1 bits

TPC NTPC bits

TFCI NTFCI bits

Data 2 NData 2 bits

Pilot NPilot

Slot #0 Slot #1 Slot #i Slot #14

One radio frame, Tf = 10 ms

Tslot = 2560 chips, 10x2k bits (K=0.7)

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time multiplexed with control information generated at layer 1 (known pilot bits, power-control commands, and an optional transport-format combination indicator). DPCH can contain several simultaneous services when TFCI is transmitted or a fixed rate service when TFCI is • not transmitted. The network determines if a TFCI should be transmitted. When the total bit rate to be transmitted exceeds the maximum bit rate for a downlink physical channel, multicode transmission is employed (i.e., several parallel downlink DPCHs are transmitted using the same spreading factor). In this case, the layer 1 control information is put on only the first downlink DPCH.Common pilot channel (CPICH) is a fixed-rate (30 Kbps, SF=256) downlink physical channel that carries a • predefined bit/symbol sequence. There are two types of common pilot channels, the primary and secondary CPICH, as shown in Table 6.6. The primary CCPCH is a fixed-rate (30 Kbps, SF=256) downlink physical channels used to carry the BCH. • Common control physical channels are not inner-loop power controlled. Figure 6.15 shows the frame structure of the primary CCPCH. The primary CCPCH is not transmitted during the first 256 chips of each slot. Instead, primary and secondary • SCHs are transmitted during this period. The secondary CCPCH is used to carry the FACH and PCH. The main difference between the primary and secondary CCPCH is that the primary CCPCH has a fixed • predefined rate while the secondary CCPCH can support variable rate. Furthermore, a primary CCPCH is continuously transmitted over the entire cell while a secondary CCPCH is • only transmitted when there is data available and may be transmitted in a narrow lobe in the same way as a dedicated physical channel (only valid for a secondary CCPCH carrying the FACH).

Primary CPICH

Uses the same channelisation code always:Scrambled by the primary scrambling codeOne per cellBroadcast over the entire cellThe primary CPICH is the phase reference for the SCH, primary CCPCH, AICH, PICH. It is also the default phase reference for all other downlink physical channels.

Secondary CPICH

Zero, one, or several per cellMay be transmitted over only a part of the cellA secondary CPICH may be the reference for the secondary CCPCH and the downlink DPCH. If this is the case, the mobile station is informed about this by higher-layer signalling

Table 6.6 Primary and secondary CPICH

Fig. 6.15 Frame structure for primary CCPCH

Slot #0 Slot #1 Slot #i Slot #14

1 radio frame: Tf = 10 ms

Data18 bits

256 chips

(Tx OFF)

Tslot = 2560 chips, 20 bits

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Fig. 6.16 Frame structure for secondary CCPCH

Figure 6.17 depicts the structure of the synchronisation channel (SCH) used for cell search. The SCH consists �of two sub channels, the primary and secondary SCH. The primary SCH consists of a modulated code of length 256 chips, the primary synchronisation code (PSC) �denoted cp in Figure 6.17, transmitted once every slot. The PSC is the same for every cell in the system.

Fig. 6.17 Structure of synchronisation channel

The secondary SCH consists of repeatedly transmitting a length 15 sequence of modulated codes of length 256 • chips, the secondary synchronisation codes (SSC), transmitted in parallel with the primary SCH. The SSC is denoted c• s

i,k, where i = 1, 2,…, 64 is the number of the scrambling code group, and k = 0, 1, …, 14 is the slot number. Each SSC is chosen from a set of 16 different codes of length 256. This sequence on the secondary SCH indicates to which of the code groups the cell’s downlink scrambling code belongs.The physical downlink shared channel is used to carry the downlink shared channel. It is shared by users based • on code multiplexing. The structure of the PDSCH is shown in Figure 6.18. As the DSCH is always associated with a DCH, the PDSCH is always associated with a downlink DPCH. For PDSCH the spreading factors may vary from 256 to 4. If the spreading factor and other physical layer • parameters can vary on a frame-by-frame basis, the TFCI shall be used to inform the mobile stations of the instantaneous parameters of PDSCH.

Slot #0 Slot #1 Slot #i Slot #14

1 radio frame: Tf = 10 ms

DataNdata bits

Pilot NPilot bits

TFCI NTFCI bits

Tslot = 2560 chips, 20x2k bits (k=0.6)

Slot #0

256 chips

2560chips

One 10 ms SCH radio frame

acp acp acp

acs i.0 acs i.1 acs i.14

Primary SCH

Secondary SCH

Slot #1 Slot #14

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Fig. 6.18 Frame structure for the PDSCH

The acquisition indicator channel (AICH) is a physical channel used to carry acquisition indicators, which • correspond to signature s on the PRACH or PCPCH. The page indicator channel (PICH) is a fixed-rate (SF=256) physical channel used to carry the page indicators. • The PICH is always associated with a secondary CCPCH to which a PCH transport channel is mapped.

6.8 Power Control in WCDMAThe power control in WCDMA can be classified into two types.

6.8.1 Uplink Power ControlThe uplink power control has two parts:

Inner loop power controlFor inner loop power control the UE transmits to the NodeB. The NodeB receives the Signal to Interferance Ration (SIR) and compares it with the target. Based on the target level the NodeB instruct the UE to increase or decrease power. This process occurs for every transmission slot (every 667 micro second).

SIRest > SIRtarget TPC = 0SIRest < SIRtarget TPC = 1

Outer loop power controlThe outer loop power control ensures the QoS for a particular UE. The outer loop power control is between the NodeB and RNC. To achieve this objective NodeB sends quality information to the RNC. The quality information is based on BER and Block Error Rate (BLER) for a specific UE. Based on this info RNC decides whether to increase or decrease the quality of the radio link.

6.8.2 Downlink Power ControlThe downlink power control has two parts:

Inner loop power controlFor inner loop power control the NodeB transmits to the UE. The UE receives the Signal to Interferance Ration (SIR) and compares it with the target. Based on the target level the UE instruct the NodeB to increase or decrease power. This process occurs for every transmission slot (every 667 micro second).

SIRest > SIRtarget TPC = 0SIRest < SIRtarget TPC = 1

Outer loop power controlThe outer loop power control ensures the QoS (Quality of Service) for a particular Node B. The outer loop power control is between the UE and RNC. To achieve this objective UE sends quality information to the RNC. The quality information is based on BER and Block Error Rate (BLER) for a specific Node B. Based on this info RNC decides whether to increase or decrease the quality of the radio link.

Slot #0 Slot #1 Slot #i Slot #14

1 radio frame: Tf = 10 ms

DataNdata bits

Tslot = 2560 chips, 20x2k bits (k=0.6)

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6.9 Multi-rate User Data TransferWCDMA offers quality of service parameters with transmits the data in multi-rate system which makes • transmission of various types of services using various type data rates. These various kinds of transmission procedure with channel coding, interleaving depth, and data rate can be aimed to provide the desired quality of service.Data stream is achieved from transport channels and then they transmit them through the transmission link • before encoding the data and mapping them to the physical channels. This channel coding method contains error detection, error correcting, rate matching, interleaving, and transport • channels mapping them together into the physical channels. Coding or multiplexing group receives the data once in between each transmission time break with the set of • transport block sets, which is set by the transport-channel and can be 10, 20, 40, or 80 ms. Multi-rate transmission includes of following procedure:

Addition CRC or cyclic redundancy check occurs to every transport block. �Transport block has to be concatenated and code block has to be segmented. �Inserts indication bits in the discontinuous transmission (DTX) �Transport channels is multiplexed �Mapping to physical channels �Channel coding �Rate matching �Interleaving �Segmentation is done in the radio frames. �Segmentation is done in the physical channel. �

Error detection is introduced in the transport blocks by CRC. The CRC has the length of 24, 16, 12, 8, or 0 bits, • and higher layers signal used for each transport channel.Concatenation of transport code and segmentation of code blocks occurs before doing CRC addition. Every • transport blocks concatenated according to serial. Then concatenation occurs in the transport block. Code block segmentation is performed if the size of transmission time break is bigger than the size of the used code block. Size of the code blocks depends on using the various kinds of code blocks. It could be convolution coding, • turbo coding, or no coding have used. The maximum size if the code blocks are:

Convolution coding: 504 �Turbo coding: 5114 �No channel coding: unlimited �

Transport format detectionTransport format detection can occur with the help of transport format combination indicator (TFCI) or without • the help of TFCI. When a TFCI is transmitted, the receiver receives the information of the transport format combination through TFCI. Blind transport format detection could be used in absence of TFCI. Receiver receives the transport format group • using some information, as an example, transport format group information can be received by power ratio of DPDCH to DPCCH or CRC check results.

6.9.1 Channel Coding

The aim of channel coding is to provide careful redundancy check into the transmitted data and increase the • functional performance of the wireless link. Channel codes could be introduced to find errors and corrects them.

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WCDMA scheme holds the prerequisite for both error detection and correction. Channel coding scheme is a bunch • of techniques contains of error detection, error correction, along with rate matching, interleaving and transport channels mapping onto/splitting from physical channels. The following channel coding can be applied:Convolutional coding with the limitation of size 9 and coding rate 1/3 or 1/2• Turbo coding• No channel coding•

6.9.2 Convolutional CodingIn telecommunication, a convolutional code is a type of error-correcting code in which:

each m-• bit information symbol (each m-bit string) to be encoded is transformed into an n-bit symbol, where m/n is the code rate (n ≥ m) andthe transformation is a function of the last k information symbols, where k is the constraint length of the code•

6.9.3 Turbo Coding

In information theory, turbo codes (originally in French • Turbocodes) are a class of high-performance forward error correction (FEC) codes developed in 1993, which were the first practical codes to closely approach the channel capacity, a theoretical maximum for the channel noise at which reliable communication is still possible given a code rate. Turbo codes are finding use in (deep space) satellite communications and other applications where designers • seek to achieve reliable information transfer over bandwidth or latency constrained communication links in the presence of data-corrupting noise. Turbo codes are nowadays competing with LDPC codes, which provide similar performance. Turbo coding • system has a eight-state elements encoders and is a parallel concatenated convolutional code (PCCC).

Transport channel type Coding scheme Coding rateBCH

Convolutional coding 1/2PCH

RACH Turbo Coding 1/3CPCH, DCH, DSCH, FACH No Coding -

Table 6.7 Error correction coding parameters

6.9.3.1 Error DetectionCRC or Cyclic Redundancy Check code performs the error detection. CRC has the length of 24, 16, 8 or 0 bits. The whole transmitted frame is assigned to compute the parity bits. Any of the following cyclic generator polynomials could be utilised to build the parity bits: g24(D) = D24+D23+D6+D5+D+1 g16(D) = D16+D12+D5+D+1 g8(D) = D8+D7+D4+D3+D+1

6.9.3.2 Error CorrectionWCDMA system has two optional way of error correction. These are:

Convolutional Coding -• Convolutional coding is to be relevant for the voice application which needs BER up to10-3. The limitation size for the projected convolutional coding system is 9. Convolutional coding of 1/2 and 1/3 have been precise.Turbo Coding - • Turbo coding is suitable for the high speed data dates which need BER from 10-3 to 10-6.

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6.10 Establishment of UMTS Speech CallThe procedure for the establishment of a basic speech call in UMTS is• shown in Figure 6.19.The process• begins with an access request from the UE, which is sent either on the RACH transports channel or the CPCH transport channel. The message sent is a request to establish an RRC connection, which must be done before the occurrence of signalling transactions or bearer establishment. The RRC Connection Request includes an indication of the reason for the connection request.The RNC responds with an RRC Connection Setup message, which• will be sent on the CCCH logical channel (typically mapped to the FACH transport channel). At the discretion of the RNC, the RRC Connection Setup message may or may not allocate a DCH transport channel to the UE.If a DCH transport channel is allocated, then the RRC Connection• Setup message indicates the scrambling code to be used by the UE in the uplink.The channelisation code is determined by the UE and is indicated• on the uplink itself.Recall, example, that a DPCCH is associated with a• DPDCH. The DPDCH contains the TFCI that contains spreading factor information and enables the UTRAN to determine the channelisation code for the DPDCH.If the RNC does not allocate a DCH, then further signalling• is carried out on the FACH in the downlink and on the RACH or CPCH in the uplink.The UE responds to the RNC with the message, RRC Connection Setup Complete, which is carried on the uplink • DCCH logical channel and mapped to the RACH, CPCH, or DCH transport channel.Next, the UE issues a message destined for the core network. This is sent in an RRC Initial Direct Transfer • message. The payload of a direct transfer message is passed directly between the UE and the core network.Here, since a signalling relationship has not been established between the UE and core network, the RRC • message Initial Direct Transfer is used. This indicates to the RNC, and subsequently to the core network, that a new signalling relationship needs to be established between the UE and the core.The RNC maps the Initial Direct Transfer message to the RANAP Initial UE message and sends the message • to the core network. In this case, the message is passed to the MSC.The choice of MSC or SGSN is made based upon header information in the Initial Transfer message from the • UE.The payload of the Initial Direct Transfer message is mapped to the payload of the RANAP Initial UE message • to the MSC.Next, the MSC will initiate security procedures. This begins with authentication, which uses a challenge-response • mechanism similar to that used in GSM. One difference, however, is that the UE and network authenticate each other.Not only does the network send a random number to the UE to which a correct response must be received, but • it also sends a network authentication token (AUTN), which is calculated independently in the USIM and the HLR.The AUTN must match what the network is expecting. The authentication request is sent to the UE using the • direct transfer messaging of RANAP and the RRC protocol.Assuming that the AUTN is acceptable, the UE responds with an authentication response message, which • contains a response that the MSC checks. This message is also carried using the direct transfer capabilities of RANAP and RRC.Then the core network will instigate encryption (ciphering) and integrity procedures. This is similar to the • ciphering that is performed in GSM, with the addition that integrity assurance is also enabled. This capability enables the network or UE to verify that signalling messages from the other entity have not been maliciously altered.Ciphering and integrity procedures are initiated by the core network, but are executed between the UE and • UTRAN.

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Therefore, the MSC sends the RANAP Security Mode Command message to the RNC. In turn, the RNC sends the • RRC Security Mode Command message to the UE. The UE responds to the RNC with the RRC message, Security Mode Complete, and the RNC responds to the MSC with the RANAP message, Security Mode Complete.At this point, the actual call establishment information such as the called party number data is sent in a Setup • message from the UE to the MSC using direct transfer signalling.Provided that the call attempt can be processed, MSC responds with the Call Proceeding message, much like • is done in GSM.Next, it is necessary to establish a Radio Access Bearer (RAB) for transport of the actual voice stream from • the user. A RAB is a bearer between the UE and the core network for the transport of user data, either speech or packet data.It is mapped to one or more radio bearers on the air interface. Each RAB has its own identifier that is used in • signalling between the UE and the network. A RAB establishment is requested by the core network through a RANAP RAB Assignment Request message.Based on the information in the RAB Assignment Request, the RNC may set up a new radio bearer for the UE • to use, or it may reconfigure any existing bearer that the UE has active.The RNC uses either the RRC message Radio Bearer Setup or the Radio Bearer Reconfiguration to instruct the • UE to use the new or reconfigured radio bearers.The UE responds with either Radio Bearer Setup Complete or Radio Bearer Reconfiguration Complete. The • RNC, in turn, responds to the MSC with the RANAP message RAB Assignment Complete.Now a bearer path exists from the UE through to the MSC.• Note that the establishment of the bearer path also requires the establishment of a terrestrial facility between • the Node B and RNC and between the RNC and MSC.The details of this establishment have not been shown in Figure 6.16. Suffice it to say that the transport • bearer (using AAL2) will be established through the transport user control plane and the ALCAP previously described.

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Fig. 6.19 Establishing a speech call in UMTS

The remainder of the call establishment is quite similar to call establishment in GSM. It involves Alerting, • Connect, and Connect Acknowledge messages carried over direct transfer signalling. It should be noted that speech service in the 3GPP Release 1999 architecture is still a circuit-switched service.Although the speech is actually packetized for transfer over the air and is also packetized as it is carried over • the Iub and Iu interfaces, a dedicated bearer is established for the duration of a call, even when discontinuous transmission is active and no speech packets are being sent.

UE RNC MSC/VLR

CCCH: RRC Connection Request

DCCH: RRC Connection Setup Complete

DCCH: Initial Direct Transfer

DCCH: Direct Transfer (Authentication Response)

DCCH: Security Mode Complete

DCCH: Direct Transfer (Setup)

DCCH: Security Mode Command

DCCH: Direct Transfer (Call Proceeding)

DCCH: Radio Bearer Setup or Reconfiguration

DCCH: Radio Bearer Setup or Reconfiguration Complete

DCCH: Direct Transfer (Altering)

DCCH: Direct Transfer (Connect)

DCCH: Direct Transfer (Connect Acknowledge)

CCCH: RRC Connection Setup

RANAP: Initial UE Message (CM Service Request)

RANAP: Direct Transfer (Authentication Response)

RANAP: Direct Transfer (Setup)

RANAP: Direct Transfer (Setup)

RANAP: Rab Assignment Complete

RANAP: Direct Transfer (Connect Acknowledge)

RANAP: Direct Transfer (Call Proceeding)

RANAP: Rab Assignment Request

RANAP: Direct Transfer (Altering)

RANAP: Direct Transfer (Connect)

RANAP: Direct Transfer (Authentication Request)

RANAP: Security Mode Complete

DCCH: Direct Transfer (Authentication Request)

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6.11 UMTS Packet Data (R99)Given below are the types and description of UMTS Packet Data.

6.11.1 GSM and UMTS Packet DataThe various approaches and elements involved in GSM and UMTS Packet Data are explained in detail below.

6.11.1.1 GPRS Elements

The GPRS system is a packet data extension of the GSM system, which was originally designed for circuit • services. GPRS enables the support of packet-based data transmission over the radio interface and packet data mobility within the core network. Deploying GPRS entails a Base Station Subsystems (BSS) software-only upgrade, which allows multiplexing • of data services over the slots not occupied by speech services, flow control, and retransmission mechanisms necessary to deliver data services over the (GSM) radio transmission technology. It also requires updating the HLR software and installing new core network nodes: the Serving GPRS Support • Node and Gateway GPRS Support Node (SGSN and GGSN). DNS, address management system, AAA, billing, and intelligent network are additional components that are parts of advanced GPRS services. The GPRS architecture and specifications were defined by ETSI and now are maintained by 3GPP. The GPRS • architecture is depicted in Figure 6.20.

Fig. 6.20 GPRS architecture

The SGSN in GPRS, also referred to as 2G SGSN, offers network layer compression services, segmentation • and reassembly functionality, logical link layer framing and multiplexing, ciphering, as well as handling MS signalling and mobility management (within the BSS, between SGSNs), and managing GTP tunnels established toward GGSNs. The SGSN also interacts with the HLR and the intelligent network, the MSC, and the SMS Service Center • (SMS-SC).The GGSN “anchors” the data communications session and provides access to packet data networks by supporting • the termination of GTP tunnels from the SGSN to which the MS is currently attached. GGSNs are also used in IP networks to provide a foundation and a gateway to advanced packet data services • such as Web browsing, WAP; remote private networks, including networks used to provide mobility support for non-roaming users (intra-PLMN network), roaming (GPRS Roaming Exchange or GRX network), and GPRS network element functions.

PDN

TEGGSN

Ga

CGF

GGSN

Data and signallingSignalling

Other PLMN

2G SGSN

BSS

Gb

Gp

MT

Um

RTE

MSC/VLR

Gs

Gr Gc

Gn Gi

HLR

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6.11.1.2 UMTS Elements

The UMTS offers packet data services over its PS domain (see the next section). Its architecture, shown in • Figure 6.21, is similar to the GPRS architecture.The same network nodes are involved in the core network, although the GTP protocol used in UMTS (GTPvl) • is not backward-compatible with the GTP protocol versions used for GPRS (GTPv0). Other differences are in the service capabilities—for instance, UMTS supports its own QoS framework along with more multimedia capabilities.Also, the UMTS SGSN, also referred to as 3G SGSN, does not terminate any link layer protocols nor provide • network layer compression or ciphering. Instead, it simply relays packets between GGSNs and Radio Network Controllers over GTP tunnels.In UMTS, the RNC function is managing mobility of MSs among the Node Bs (UMTS base stations), which • it controls transparently to the UMTS PS domain.According to one of the UMTS fundamental principles, the RAN details must be hidden from the core. This is • one of the reasons why all the UMTS link layer functionality has been moved from SGSN to the RNC.

Fig. 6.21 3GPP UMTS architecture

6.11.2 GPRS and UMTS PS Domain System Architecture

The GPRS system defines mainly two components:• the BSS �the PLMN backbone �

The GPRS BSS is the GSM BSS augmented with a Packet Control Unit (PCU) that is used to upgrade the GSM • BSS to support packet services.The PLMN backbone includes two new nodes introduced previously:•

SGSN �GGSN �

The GGSN and the SGSN are connected via an IP network and interact via the Gn interface, based on the GTP • protocol.When a user roams, that user attaches to a SGSN in the visited network and a GGSN in either the home network • or the visited network.If the GGSN is in the home network, the IP network used to connect the visited SGSN to the home GGSN is • named the Inter-PLMN Backbone Network.The Inter-PLMN Backbone Network is usually offered by network service providers under the name GPRS • Roaming Exchange (GRX), which was defined by the GSM association.

PDN

TEGGSN

Ga

CGF

GGSN

Data and signallingSignalling

Other PLMN

3G SGSN

UTRAN

Iu-PS

Gp

MT

Uu

RTE

MSC/VLR

Gs

Gr Gc

Gn Gi

HLR

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Candidates to operate the GRX network have to comply with requirements set forth by the GSM Association.• A curious aspect of GPRS as it relates to GRX is that the SGSN in the visited network and the GGSN in the • home network interact over GRX network via an interface, called Gp, which is entirely identical from a protocol perspective to the Gn interface.The UMTS system takes into account from the outset the need of supporting both a packet-switched (PS) core • network and a circuit-switched (CS) core network.One of the principles for general 3G access network specifications has been independence of the core network • from the radio interface and support of multiple cores. GPRS specifications define new protocol layers in the BSS—Radio Link Control (RLC) and Medium Access • Control (MAC)—that enable the usage of the existing GSM framing structure for GPRS.The GSM system specification allows for the usage of one to eight time slots in both uplink and downlink.• The standard specs define the way to adapt different network protocols to the logical link service offered by • this system—Sub-Network Dependent Convergence Protocol (SNDCP)—by relaying Logical Link Control (LLC) frames between the MS and the SGSN. This relay functionality is provided by the PCU, which enables enhancements of the GSM BSS to become GPRS services-capable.The GSM RAN, augmented with the PCU functionality, is connected to the GPRS core via the Gb interface, • which defines a Frame Relay-based network service on top of which the base station subsystem GPRS protocol (BSSGP) is carried (Figure 6.22).BSSGP is used to support logical channels on top of the Frame Relay network service. These logical channels • are used to implement an LLC protocol frame’s routing between the BSS and the core, so that the BSC+PCU can route LLC frames to the correct cell.In the uplink, the BSSGP carries the cell ID information, and any LLC frame transported on the BSSGP protocol • can offer location information.Typically, an MS updates the location (cell update) when it is with an active session (sending and receiving • data) by sending an LLC frame.

Fig. 6.22 The GPRS user plane and control plane

IP

SNDCP

LLC

RLC RLC BSSGP BSSGP

LLCGTP

UDP/IP

L2 L2

L1 L1

L1

SNDCP

FR FR

Relay

Relay

IP

GTP

UDP/IP

L2

GPRS User Plane

UMTS User Plane

MAC MAC

phy phy

Um

MS

IP

PDCP PDCP GTP-U GTP-U GTP-U

GTP-U

IP

UDP/IP UDP/IP UDP/IP UDP/IP

L2

L2

L2

L1

L1

L1

AALS AALS

ATM ATM

Relay Relay

RLC RLC

MAC MAC

phy

Uu

MS UTRAN 3G-SCAN 3G-GGSN

Iu-PS Gn Gi

phy

UTRAN 3G-SCAN 3G-GGSN

Gb Gn Gi

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SNDCP, LLC, and BSSGP—as well as the Frame Relay-based network service—are terminated at the 2G SGSN. • Since both user traffic and control information are transported over these protocols, and the link layer services to the mobile are terminated at the 2G SGSN, a 2G SGSN is particularly complex.This complexity potentially brings severe limitations on its scalability.• In part to address this situation, during the UMTS standards development, the decision was taken not to terminate • link layers at the SGSN, thus reducing the complexity of this element and enabling it to scale to support many more subscribers and a wider coverage area.Scaling an SGSN to cover wider area is important to minimize mobility management signalling associated to • handoff and to allow the handoffs to be, on the average, smoother. User packets are transferred over the Iu-PS using GTP/UDP/IP transport, and then relayed by the RNC toward • the MS using radio link protocols (PDCP/RLC/MAC). Packed Data Convergence Protocol (PDCP) functionality in UMTS is similar to SNDCP in GPRS.It also supports header compression protocols that are particularly useful for reduction of the overhead for • real-time applications—in particular, for future Voice over IP (VoIP) applications that will be characterising the evolution of the UMTS system.The RLC and MAC layers are used to implement the radio link layer. They implement the logical link layer • channels over the W-CDMA radio interface physical layer.The Mobile Terminal communicates control information to the GPRS or UMTS core network using a Radio • Interface Layer 3 protocol (RIL3) specified in [3GPP TS 24.008]. This includes GPRS (or packet, in UMTS) mobility management and session management. In GPRS, RIL3 is carried over the LLC NULL channel and is handled by the SGSN on the core network side.In UMTS, this protocol is transported using the direct transfer procedure over the RANAP protocol.• The SGSN elaborates control information from the terminal, and as a consequence, it can interact with other • entities in the network. Example, it can open MAP dialogues with the HLR for security procedures, subscriber information retrieval, or location update purposes.It also can interact with the intelligent network via the CAMEL [3GPP TS 23.078] interface, for instance, to • offer prepaid data services to GPRS users.Packed data sessions in GPRS and UMTS are established by setting up and maintaining GTP tunnels toward • GGSNs. A GTP tunnel is an encapsulation of the user packets between the GGSN and the SGSN in GTP/ UDP/IP. Another function of the SGSN is the collection of charging data and communication to a Charging Gateway • Function (CGF) over the Ga interface.The Ga interface is based on the GTP protocol [3GPP TS 32.015].• The SGSN can also support SMS services via the Gd interface to SMS-GMSC and interact with the MSC/VLR • via the Gs interface for paging coordination and combined location update.

6.11.3 GPRS and UMTS PS Domain Service Capabilities

The GPRS and UMTS PS domain systems are in principle multi-protocol and neutral to the nature of the network • layer or link layers of the user traffic.The user protocols are also called Packet Data Protocols (PDPs). The type of protocol is identified with the • term “PDP type.”Initially, the GPRS system supported many more PDP types than were actually implemented and deployed.• GPRS provides support for both IPv4 and IPv6, but IPv6 cannot be realistically expected to see deployment • until sometime in 2004.It is supporting PPP type PDP starting from R98, but unfortunately, terminal vendors did not rush to implement • the support of this PDP type, and we haven’t seen any real support of this PDP type as yet.In fact, we have witnessed an unexpected amount of controversy surrounding this PDP type.•

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Some vendors have tried to remove it from the standard, despite the fact that in principle this PDP type would • prove to be beneficial in offering advanced data services such as access to private networks.The GPRS and UMTS PS domain systems offer an unreliable transport channel from the GGSN to the MS.• This channel can be characterised by a number of QoS parameters, which are different for releases prior to R99 • and releases from R99 onward.In R99 and later releases, it is possible to differentiate the handling of packets belonging to the same user • session.This is accomplished by establishing multiple bearers (PDP contexts) of different traffic class and QoS profile, • associated with the same session, and by forwarding packets on to the appropriate bearers based on some classification rules established at the GGSN and at the MS.This capability has been introduced because of the requirement of offering multimedia capabilities via the UMTS • system, at the basis of the service aspects expected from 3G cellular systems.In R98, instead, only one level of QoS (and only one PDP context) can be associated to a session.•

6.11.4 GPRS and UMTS PS Domain Terminal

There are three different classes of GPRS MS:• Class A: � This class allows for concurrent support of GSM and GPRS servicesClass B: � In this class, the MS monitors both GSM and GPRS paging channels, but only one service can be supported at a timeClass C: � In this class, the MS only supports GPRS service (as a data-only device)

Class A terminals require two separate GSM transceivers operating on different frequencies, with independent • packet and circuit services. Because of the complexity of such terminals, in R99, operators and manufacturers targeted for the definition of terminals supporting Dual Transfer Mode (DTM).From a service perspective, this approach still offers the simultaneous coexistence of GPRS and GSM voice • services like in a Class A terminal, but from a paging perspective they are more similar to a Class B device and require a single transceiver.This approach is made possible via an upgrade of the BSS to route paging over the same channel as used for • GPRS, when the MS is GPRS-attached.Note that this enables the paging coordination to happen in the BSS, much like in UMTS systems.• A Mobile Terminal capable of UMTS PS or GPRS access can either be:•

An integrated device offering computing and wireless data access in one physical unit �Composed of two components: one devoted to wireless access and the other a data applications capable �device

The latter configuration is similar to today’s laptops, which are equipped with PCMCIA modem cards or a serial • connection to a modem.In fact, the 3GPP standards [3GPP TS 29.061], [3GPP TS 27.060] define the existence of two logical components • of the MS: the Terminal Equipment (TE) and the Mobile Termination (MT).The TE is the computing-capable part of the MS.• The MT is the part devoted to the support of the wireless data access capabilities.• When the TE and MT are implemented as separate physical entities, they can be connected by multiple technologies • (serial, infrared, Bluetooth, etc.) with the link layer based on PPP, or another proprietary interface.Indeed, this interface may be internal between components of a single physical package, rather than between • physically distinct entities.When the PPP interface is used between the TE and MT, the IP PDP type can still be used, but the authentication • and configuration material is not transported between the GGSN and the MT using PPP.Rather, it is encapsulated in a Protocol Configuration Options Information Element (PCO IE), transparently • relayed between RIL3 and GTP by the SGSN.

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This way, PPP exists between the TE and MT, but not between the MT and the GGSN. This access mode is • called non-transparent IP access.Mobile Terminals also often come with dual-mode GPRS/GSM and UMTS capability, since many operators will • roll out UMTS starting from densely populated and capacity-strained areas, and rely on GPRS for the handling of users in areas where only 2G coverage exists.In fact, this will be one of the most commonly requested terminal features in the early days of UMTS.•

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SummaryUMTS is specified and implemented as an end-to-end mobile system and represents an evolution in terms of • capacity, data speeds and new service capabilities from second generation mobile networks.The basic architecture of the UMTS is modelled on the lines on the GSM/GPRS network architecture. The radio • access for UMTS is known as Universal Terrestrial Radio Access (UTRA). This is a WCDMA-based radio solution, which includes both FDD and TDD modes.The radio access network (RAN) is known as UTRAN. It takes more than an air interface or an access network • to make a complete system. However, the core network must also be considered.Data stream is achieved from transport channels and then they transmit them through the transmission link • before encoding the data and mapping them to the physical channels.The GPRS system is a packet data extension of the GSM system, which was originally designed for circuit • services. GPRS enables the support of packet-based data transmission over the radio interface and packet data mobility within the core network.

ReferencesB. G. Evans and K. Baughan, (December 2002). Visions of 4G, Electronics and Communication Engineering • Journal.C. Kikkert, (2004). • Digital Communication Systems and their Modulation Techniques, James Cook University, 4th edition.H. Honkasalo, K. Pehkonen, M. T. Niemi, and A. T. Leino, (2002). • WCDMA and WLAN for 3G and Beyond. IEEE Wireless Communications, 9(2):P14–18.Lars Ahlin, Jens Zander, (1998). • Principal of Wireless Communications, Studentlitteratur.T. Ojanpera and R. Prasad, (editors), (1998). • Wideband CDMA for Third Generation Mobile Communications. Artech House Publishers.William Stallings, (2003). • Wireless Communications and Networking, Prentice Hall.

Recommended ReadingEsmael H. Dinan and Bijan Jabbari, Spreading Codes for Direct Sequence CDMA and Wideband CDMA Cellular • Networks, IEEE Communications Magazine, vol. 36, September 1998.Kevin Laird, Nick Whinnet, and Soodesh Buljore, (1999). A Peak-To-Average Power Reduction Method for • Third Generation CDMA Reverse Links, in Proc., IEEE Vehicular Technology Conference.Theodore S. Rappaport, (2002). • Wireless Communications: Principles & Practice, Prentice Hall.

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Self Assessment

AT & T now offers subscribers a number of UMTS ________ phones.1. 850/1900a. 850/1800b. 850/1700c. 850/1600d.

Each SSC is chosen from a set of _________ different codes of length _________.2. 18, 236a. 24, 256b. 16, 256c. 20, 336d.

HSPA supports increased peak data rates of up to _________ Mbits.3. 12a. 13b. 14c. 15d.

W-CDMA uses the 4. DS-CDMA channel access method with a pair of ___________ MHz channels.4a. 5b. 6c. 7d.

NextG operates in the _______ MHz band.5. 850a. 860b. 870c. 880d.

In India BSNL have started its 3G services since __________ beginning with the larger cities.6. Sept. 2009a. October 2009b. Nov. 2009c. Dec. 2009d.

In WCDMA Air Interface, the carrier spacing has a raster of ___________ kHz.7. 200a. 210b. 220c. 230d.

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Common pilot channel (CPICH) has a fixed-rate downlink physical channel of ___________ Kbps.8. 20a. 30b. 40c. 50d.

SCH consists of a modulated code of length _______ chips.9. 128a. 256b. 512c. 1024d.

CDMA2000 system uses one or more arbitrary _______ MHz channels for each direction of communication.10. 1.25a. 1.26b. 1.27c. 1.28d.

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Chapter VII

Web Based Management and Web Based Element

Aim

The aim of this chapter is to:

explain web based management and its components•

analyse the web based element architecture•

discuss storage area network and its future trend•

Objectives

The objectives of this chapter are to:

define web based management and web based element management•

figure out the architecture of web based element management•

explain Java Management Extensions and its three level architecture•

Learning outcome

At the end of this chapter, the students will be able to:

get an overview of web based management and embedded web based management•

understand the architecture of Java Management Extensions and web based enterprise management and storage •

area network

defi• ne web based enterprise management and its usability

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7.1 Web Based ManagementIn modern era, web technology is very rapidly developing in many organisations. The technology is based on Internet and offers a number of benefits in terms of efficiency and accessibility of its standards and tools. The ability to use a universal browser to access management functions, device status and statistics, and to configure remote managed objects from anywhere at any time and give many advantages to a network administrator. For developers, system development cost and time can be saved by standardising on browser instead of workstations, and by use of existing standards and numerous supporting tools.

There are two approaches for Web Based Management:Web-Based Enterprise Management (WBEM)• is a set of management and Internet standard technologies developed to unify the management of distributed computing environments. WBEM provides the ability for the industry to deliver a well-integrated set of standard-based management tools, facilitating the exchange of data across otherwise disparate technologies and platforms.The Java Management Extension (JMX)• technology provides the tools for building distributed, Web-based, modular and dynamic solutions for managing and monitoring devices, applications, and service-driven networks. By design, this standard is suitable for adapting legacy systems, implementing new management and monitoring solutions, and plugging into those of the future.

7.2 Embedded Web Based ManagementThe web technology is applied into the network management by embedding web server into the network device. • This concept is called as embedded web based management. The web server is called as Embedded Web Server (EWS). User interface which is provided by web server is constructed with HTML and graphics. Fig. 7.1 shows the • web based element architecture.

Fig. 7.1 Web based element architecture(Source: Embedded Web Server Architecture for Web-based Element and Network Management)

Embedded Web Server has some special requirements like low resource utility, high reliability, security and • portability. In other hand general web servers are unsuitable for that.

7.3 Web based Network Management In an Embedded Web Based Management number of switches, hubs are used which are very tedious and • difficult to manage. If there are many EWS embedded in network device, then an administrator must open a web browser for each device.

Internet

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In Web-based network management, the manager runs as an application over the operating system, and collects • information gathered from the network and systems device to the browser. In doing so, the manager needs a standard access protocol in order to support a multi-vendor environment.HTTP is used as a management protocol between manager and agent. One standard format should be developed • for exchange of data between two programs over HTTP.

Fig. 7.2 Web based network management architecture(Source: Embedded Web Server Architecture for Web-based Element and Network Management)

Web Based Management Agent and Web Based Management manager perform the task of manager and agent. The • information between these two is exchange between XML and HTTP. XML is used in network management. WBM manager is a XML based web client application and WBM agent is a specialised web server which • provides management information in XML format. Because of the some advantages like:

user-defined vocabulary �self-describing �structured information �manipulated by standard mechanism �

7.4 Web Based Enterprise ManagementIt is a combination of management standards which are integrated with regular internet standard. The main objective behind Web Based Enterprise Management (WBEM) is to unify the enterprise management into a single standard.

Developer of WBEM: • It is developed by Distributed Management Task Force (DMTF), which consists of large numbers of companies dealing with network management scene. Some of the major companies are like Sun micro system, Microsoft, Cisco, Intel, 3Com Corporation, Compaq etc. Usability of WBEM: • There are number of equipment manufacture who, develops product which, supports WBEM. For example there are some Network management systems called BMC Patrol and Cisco works which manage the elements with WBEM interfaces.

Data Repository

WBM Manager

For Long-term Analysis

Web pages HTTP

Web pages HTTP

XML/HTTP

WBM Agent

WBM Agent

WBM Agent

Device Device Device

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Components of WBEM: • The entire structure of WBEM is build around Common Information Model (CIM). CIM is an object oriented representation which contains standard models for lots of different equipments like computers, networks, devices and applications. There must be a WBEM client and WBEM server. WBEM server consists of CIMOM (CIM Object Manager) and an interface to communicate with a WBEM client. Similarly, WBEM client is a management application which is the consumer of WBEM data. Client does not directly access the data from the provider but it gets the information from the CIMOM.

Fig. 7.3 Structure of WBEM elements(Source: LULEA Teknisk University)

Another standard which is used in WBEM is Managed Object Format (MOF). It is a textual representation of • CIM. WBEM server usually contain MOF compiler which compiles MOF text files into CIM form, then it is used by CIMOM.

7.5 Java Management ExtensionThe Java Management Extensions (JMX) defines architecture, the design patterns, the APIs, and the services for application and network management and monitoring in the Java programming language.

The architecture of JMX is divided into three parts:instrumentation level• agent level• distributed service level•

WBEM Client

HTTP – XML

WBEM Server

CIMOM

WBEM Provider

WBEM Provider

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Fig. 7.4 JMX architecture(Source: Sun Micro System Inc)

7.5.1 Instrumentation Level

The instrumentation level provides a specification for implementing JMX manageable resources. A JMX • manageable resource can be an application, an implementation of a service, a device, a user, and so forth. It is developed in Java, or at least offers a Java wrapper, and has been instrumented so that it can be managed • by JMX-compliant applications.The instrumentation is provided by one or more Managed Beans, or MBeans, that are either standard or • dynamic. Standard MBeans are Java objects that conform to certain design patterns which are derived from Java Beans.

7.5.2 Agent Level

The agent level provides a specification for implementing agents. Agents are usually located on the same machine • as the resources they control, although this is not a requirement. This level makes the use of the instrumentation level, to define a standardised agent to manage JMX manageable • resources.

7.5.3 Distributed Service Level

The distributed services level provides the interfaces for implementing JMX managers. This level defines •

JMX - complaint Management Application

C

C CPA

Web BrowserProprietary Management

Application

Distributed Services Level

Agent Level

Instrumentation Level Resource 1

(MBean)

Resource 2(MBean)

Additional Management Protocol APIs

SNMP Manager API

CIM/WBEM API

TMN Manager API

Java virtual machine (host 1)

Current JMX specification Separate JSRs

Future phases of the JMX specification

(host2)

MBean Server

Agent Services (as MBeans)

JMX Manager

Connectors and Protocol Adaptors

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management interfaces and components that can operate on agents or hierarchies of agents. The various components are like:

an interface for management application which interacts with agent and JMX manageable resource �distribution of management information from high level management to JMX agent �security provider �consolidation of information from JMX agent to logical view which is used for various business �operations.

7.6 Storage Area NetworkTraditionally, data storage resides on hard disks that are locally attached to individual servers. This is known �as Direct Attached Storage (DAS). Although this storage may now be large (in the order of 100s of Gigabytes of data storage per server) the storage is generally only accessible from the server to which it is attached. As such, much of this disk space remains unused and plenty of ‘contingency’ has to be built into storage �needs when determining server specification. In addition, if the server were to fail, access to the data held on those local disks is generally lost.In the current business world and in highly competitive environment the major challenge for any organisation �is storing of data. In order to meet the demand of data storage area network comes to the picture. The main purpose of storage area network is transmitting the data between storage system and storage �system or storage system and client servers. It contains storage components, devices, computer equipments, software applications, and network devices.

Fig. 7.5 Storage Area Network (SAN)(Source: Infortrend Technologies)

7.6.1 SAN Management Software

SAN Management software is needed to configure and monitor the components of the SAN. It is directly • concerned with enabling and controlling the movement of data within the SAN infrastructure.SAN Management products are typically able to:•

discover devices attached to the SAN i.e., hosts, storage devices, switches and other fabric components �manage and monitor ports on the Fibre Channel switches �

Clients

Servers

LAN

SANHubs, Bridges, Switches

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administer zoning on the switches to selectively enable access �administer LUN masking in the storage arrays to partition access to particular servers �monitor traffic levels and performance between components and through the switches �manage configuration changes within the SAN �

7.6.2 Road Ahead

As per Gartner report there was no SAN before 1998. In 2002 SAN is first deployed in 98% large scale industry • and 12% small scale industry. SAN is one of the emerging technologies which is used in System area network and is having higher bandwidth • and speed which is up to 10Gb/s.Security is one of the major challenges in today’s business world. Security for data security for information is • one of the crucial parts for any organisation. Some of the major security threats are like:

theft of critical information by an outsider hackers �locked but still insecure data centre �security threats from insiders �

Today Tomorrow Future

Fig. 7.6 Future of SAN(Source: Henry Yang, McData Corporation)

Storage

SwitchSwitch

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Switch Switch Switch Switch SwitchSwitch

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SummaryWeb technology is very rapidly developing in many organisations. It is based on Internet and offers a number • of benefits in terms of efficiency and accessibility of its standards and tools.The web technology is applied into the network management by embedding web server into the network device. • This concept is called as embedded web based management. The web server is called as Embedded Web Server (EWS).In an Embedded Web Based Management number of switches, hubs are used which are very tedious and difficult • to manage. If there are many EWS embedded in network device then an administrator must open a web browser for each device. The Java Management Extensions (JMX) defines architecture, the design patterns, the APIs, and the services • for application and network management and monitoring in the Java programming language.SAN Management software is needed to configure and monitor the components of the SAN. It is directly • concerned with enabling and controlling the movement of data within the SAN infrastructure.In the current business world and in highly competitive environment, the major challenge for any organisation • is storing of data. In order to meet the demand of data storage area network comes in to the picture.

References Henery Yang, (2003). • The Future of Storage Area Network. McData Corporation. Infortrend Technology, (2007). Storage Area Network.• James Won-Ki Hong, (2001). • Embedded Web Server Architecture. Department of Computer Science and Engineering.Kristopher Sandlund., (2001). • Web Based Enterprise Management. Lulea Tekniska University.Steve Chidlow, (2003). Storage Area Networks. JISC Technology and Standards Watch Report. University of • Leeds.Sun Microsystems, Inc., (2006). Java Management Extensions (JMX).•

Recommended ReadingB. G. Evans and K. Baughan, (2002). Visions of 4G, Electronics and Communication Engineering Journal.• H. Honkasalo, K. Pehkonen, M. T. Niemi, and A. T. Leino, (2002). WCDMA and WLAN for 3G and beyond. • IEEE Wireless Communications, 9(2):P14–18.T. Ojanpera and R. Prasad, (editors), (1998). • Wideband CDMA for Third Generation Mobile Communications. Artech House Publishers.

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Self Assessment

How many approaches are there in Web Based Management?1. Onea. Twob. Threec. Fourd.

_____________ is a set of management and Internet standard technologies.2. Web-Based Enterprise Managementa. Java Management Extensionb. Web-Based Managementc. Storage Area Networkd.

Traditional data storage is known as _______________.3. storage area networka. Java management Extensionb. direct attached storagec. embedded web serverd.

The ____________ provides a specification for implementing JMX manageable resources.4. management levela. instrumentation levelb. agent levelc. distributed leveld.

The ___________ provides a specification for implementing agents.5. distributed levela. agent levelb. instrument levelc. management leveld.

The instrumentation is provided by one or more _________, which are either static or dynamic.6. Java beansa. entity beansb. session beansc. managed beansd.

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The architecture of JMX is divided into how many parts?7. Onea. Twob. Threec. Fourd.

Which of the following is the standard of WBEM?8. MOFa. CIMOMb. JMXc. WBMSd.

The entire structure of WBEM is build around ________________.9. CIMa. CIMOMb. MOFc. JMXd.

_________ is used as a management protocol between manager and agent.10. FTPa. WWWb. HTTPc. SNMPd.

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Application I

Video Monitoring

With rapid economic development in China, transportation has increasingly become an extremely important component in the national economy and daily life. So it is very essential to build a modern intelligent traffic control system in order to resolve the traffic congestion of roads and reduce accidents. Video monitoring and traffic information transmission in this system plays an important role. Intelligent traffic for solving urban traffic management has become the people’s consensus such as advanced and sophisticated video surveillance system as an important component of intelligent transportation for image acquisition, on-site snapshot, after taking of evidence and other important tasks. Monitoring systems are usually installed on the expressway, traffic junctions, toll stations and other key places according to the actual needs of current traffic monitoring. All the information is integrated to the monitoring centres.

The traffic management monitoring systems are based on the IPC as a host computer, and deploy dedicated monitoring configuration software. This method is not only costly, inefficient, but also troublesome for the system to update, and specialized training for management personnel, and restricted by space-time and geography. Moreover, some information cannot be shared for public information services. With the rise of the Internet technology, embedded Web technology goes into the mainstream at present, and CGI script and Web server support the program running on an embedded device. The managers can manage and monitor situations of traffic through the Web browsers.

Questions

What is Embedded Web Server?1. AnswerThe web technology is applied into the network management by embedding web server into the network device. This concept is called as embedded web based management. The web server is called as Embedded Web Server (EWS). User interface which is provided by web server is constructed with HTML and graphics. Embedded Web Server has some special requirements like low resource utility, high reliability, security and portability.

Write a note on Web Based Management.2. AnswerWeb technology is very rapidly developing in many organisations. The technology is based on Internet and offers a number of benefits in terms of efficiency and accessibility of its standards and tools. The ability to use a universal browser to access management functions, device status and statistics, and to configure remote managed objects from anywhere at any time and give many advantages to a network administrator. For developers, system development cost and time can be saved by standardising on browser instead of workstations, and by use of existing standards and numerous supporting tools. There are two approaches for Web Based Management

Web-Based Enterprise Management �Java Management Extension �

Web-Based Enterprise Management (WBEM) is a set of management and Internet standard technologies developed to unify the management of distributed computing environments. WBEM provides the ability for the industry to deliver a well-integrated set of standard-based management tools, facilitating the exchange of data across otherwise disparate technologies and platforms.

The Java Management Extension (JMX) technology provides the tools for building distributed, Web-based,

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modular and dynamic solutions for managing and monitoring devices, applications, and service-driven networks. By design, this standard is suitable for adapting legacy systems, implementing new management and monitoring solutions, and plugging into those of the future.

How video monitoring helps in traffic system?3. AnswerVideo monitoring and traffic information transmission in this system plays an important role. Intelligent traffic for solving urban traffic management has become the people’s consensus such as advanced and sophisticated video surveillance system as an important component of intelligent transportation for image acquisition, on-site snapshot, after taking of evidence and other important tasks. Monitoring systems are usually installed on the expressway, traffic junctions, toll stations and other key places according to the actual needs of current traffic monitoring. All the information is integrated to the monitoring centre.

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Application II

Optical Metro Area Networks in Bangladesh

Sandwiched between optical local area networks and the long haul backbones, the optical Metropolitan Area Network (MAN) is evolving at a tremendous rate. It is rapidly becoming a highly competitive market driven by the rise in demand for a broad range of data communication services such as remote applications, high volume information storage, web-hosting, video on demand, and other IP-centric needs as well as bandwidth flexibility at a low cost. Each customer will have different capacity and quality of service requirements. But the creation of new data services based on SONET infrastructure has suffered major impediments due to the inherent inefficiencies of the latter: SONET has large fixed bandwidth granularity (1.5Mb/s, 50 Mb/s, 150 Mb/s, 600 Mb/s etc.,) leading to stranded capacity. Gigabit Ethernet or Optical Ethernet, on the other hand offers bandwidth in small granular increments (1 Mb/s).

This highly attractive feature of Gigabit Ethernet has led to the formation of Metro Ethernet Forum (MEF) consisting of component and system vendors, new and established telecommunication carriers with the aim to accelerate the adoption of optical Ethernet and making it the technology of choice in the world’s metro area networks. Another one of the key capabilities of this technology is that it is cost competitive in the 40-70 km range and therefore suited to MAN applications; it is eight times cheaper than either SONET or ATM. However, since Ethernet was not originally designed with carrier grade features in mind, one of its pitfalls is that it suffers from network reliability issues. Although optical Ethernet is now serving a niche market, it is continually improving thus making it a serious contender for the metro application.

QuestionsEnlist the benefits of Metro Ethernet Forum.1. How optical Ethernet is helping in metro application?2. Which is the most attractive feature of Gigabit Ethernet, according to you?3.

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Application III

WBEM Solution of HP

WEBM is a DMTF (Distributed Management Task Force) built on CIM (Common Information Management) model. WBEM allows the end user to operate the system in various platforms and operating system. It also gives the solution for optimisation in infrastructure with a greater efficiency.

Retrieving system information and requesting system operation is one of the management applications of WBEM. Various HP WBEM solutions are like:

HP WBEM services: It provides industry standard enterprise management frame work and resource information. It is also being extended and uses internet standards. Past resource can easily being retrieve from this management application which is helpful for developers.

HP WBEM providers: It provides data for device type and memory configuration so to make perfection in specific device.

HP WBEM client: This is WBEM enabled management application that provides the user interface and functionality system administrators need to manage their environment.

HP WBEM SDK: This allows developers to develop WBEM clients and providers.

QuestionsWrite down the working process of WBEM.1. What are the various solutions of WBEM?2. Write a short note on DMFT.3.

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Bibliography

References B. G. Evans and K. Baughan. Visions of 4G, Electronics and Communication Engineering Journal, December • 2002.C. Kikkert, (2004). • Digital Communication Systems and their Modulation Techniques. James Cook University, 4th edition.Data Communication and Network. Available at: <http://www.nios.ac.in/srsec330/330L5.pdf> Last accessed • 15th February 2011.Enterprise Management Systems Part I: Architectures and Standards. Deepak Kakadia, Sun Microsystems, Inc., • Dr. Tony G. Thomas, AdventNet, Inc., Dr. Sridhar Vembu, Adventnet, Inc., Jay Ramasamy, AdventNet, Inc., Sun BluePrintsTM OnLine - April 2002. Last accessed 5th March 2011.Enterprise System Management. (2001). Daniel J. Oberst. Available at: <http://net.educause.edu/ir/library/pdf/• ERM0127.pdf> Last accessed 5th March 2011.H. Honkasalo, K. Pehkonen, M. T. Niemi, and A. T. Leino, (2002). WCDMA and WLAN for 3G and beyond. • IEEE Wireless Communications. 9(2)P14–18.Henery Yang, (2003). • The Future of Storage Area Network. McData Corporation. Information Model Architecture. (2008), Available at: <. http://www.esv.se/download/18.6dae77a0113497f158• 680002589/NES+Information+Model+Architecture+-+Version+2.pdf> Last accessed 15th February, 2011.Infortrend Technology, (2007). Storage Area Network.• International Engineering Consortium. • http://www.iec.org/ Internetworking Technologies (2008). Available at: <http://faculty.kfupm.edu.sa/coe/marwan/richfiles/• Chapter%2055%20%28Remote%20Monitoring%29.pdf> Last accessed 15th February 2011.Interpeak. Simple Network Management Protocol., (2005). Available at: <http://www.interpeak.com/files/snmp.• pdf> Last accessed 15th February, 2011. James Won-Ki Hong, (2001). • Embedded Web Server Architecture. Department of Computer Science and Engineering.Kristopher Sandlund., (2001). • Web Based Enterprise Management. Lulea Tekniska University.Lars Ahlin, Jens Zander, (1998). • Principal of Wireless Communications, Studentlitteratur.Louise Clark, (2006). Network Mapping as a Diagnostic Tool Manual, CIAT 2006. Available at: <http://revista-• redes.rediris.es/webredes/talleres/networkmapping_LC06.pdf> Last accessed 28th February 2011. Mani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.Mark Burgess, (2004). • Principles of Network and System Administration. Wiley Dreamtech. 634 pages.Morris, • Network Management, Pearson Education.Network Management and Monitoring Overview. (2009). Nadi, Fiji. Available at: <http://www.pacnog.org/• pacnog6/presentations/linux-network/network-management.pdf> Last accessed 5th March 2011.SNMP Concept. Available at: (2008).<http://www.loriotpro.com/Products/On-line_DocumentationV3/• LoriotProV3Doc/C3-Introduction_to_Network_Supervision/C3-B2_SNMP_Concepts.htm> Last accessed 15th February, 2011.SNMP: Simple Network Management Protocol. Available at: < http://www.javvin.com/protocolSNMP.html> • Last accessed 1st March 2011.Solution for System Management. October 2008. Available at: <http://images.apple.com/education/docs/Apple-• SolutionsSystemMgmt.pdf> Last accessed 5th March 2011.Standardise System Management. (2009). Available at: <http://www.altiris.com/upload/wp-standardized_• systems_management_v1.3.pdf> Last accessed 5th March 2011.

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Steve Chidlow, (2003). Storage Area Networks. JISC Technology and Standards Watch Report. University of • Leeds.Sun Microsystems, Inc., (2006). Java Management Extensions (JMX).• System Management Bus Specification. Available at: <http://smbus.org/specs/smbus20.pdf> Last accessed 5• th March 2011.T. Ojanpera and R. Prasad (editors), (1998). • Wideband CDMA for Third Generation Mobile Communications. Artech House Publishers.William Stallings, (2003). • Wireless Communications and Networking, Prentice Hall.

Recommended ReadingB. G. Evans and K. Baughan, (2002). Visions of 4G, Electronics and Communication Engineering Journal.• Data Communication and Network. Available at: <http://www.nios.ac.in/srsec330/330L5.pdf> Last accessed • 15th February 2011.Esmael H. Dinan and Bijan Jabbari, Spreading Codes for Direct Sequence CDMA and Wideband CDMA Cellular • Networks, IEEE Communications Magazine, vol. 36, P48–54, September 1998.H. Honkasalo, K. Pehkonen, M. T. Niemi, and A. T. Leino, (2002). WCDMA and WLAN for 3G and beyond. • IEEE Wireless Communications, 9(2):P14–18.Kevin Laird, Nick Whinnet, and Soodesh Buljore. A Peak-To-Average Power Reduction Method for Third • Generation CDMA Reverse Links, in Proc., IEEE Vehicular Technology Conference, 1999.Mani Subramanian; Timothy A. Gonsalves; N. Usha Rani, (2010). • Network Management: Principles and Practice. Pearson Education India. 726 pages.Mark Burgess, (2004). • Principles of Network and System Administration. Wiley Dreamtech. 634 pages.Morris, • Network Management, Pearson Education.Paul, • Distributed Network Management, John Wiley.T. Ojanpera and R. Prasad, (editors), (1998). • Wideband CDMA for Third Generation Mobile Communications. Artech House Publishers.Theodore S. Rappaport, (2002). • Wireless Communications: Principles & Practice, Prentice Hall.

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Self Assessment Answers

Chapter Ia1. a2. a3. a4. b5. a6. b7. a8. a9. d10.

Chapter IIc1. a2. a3. a4. a5. a6. c7. a8. a9. a10.

Chapter IIIa1. a2. b3. a4. b5. a6. a7. a8. b9. b10.

Chapter IVa1. c2. a3. a4. b5. c6. a7. d8. c9. a10.

Network Management

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Chapter Va1. c2. d3. b4. a5. c6. b7. a8. a9. a10.

Chapter VIa1. c2. c3. b4. a5. b6. a7. b8. b9. a10.

Chapter VIIb1. a2. c3. b4. b5. d6. c7. a8. a9. c10.