chapter 19: network management

Chapter 19:Network Management

Business Data Communications, 4e

Business Data Communications, 4e 2

Network Management Requirements

Fault Management Accounting Management Configuration and Name Management Performance Management Security Management


Fault Management

A fault is an abnormal condition that requires management attention (or action) to repair

Fault is usually indicated by failure to operate correctly or by excessive errors

Users expect quick and reliable resolution


Responding to Faults

When faults occur, it is critical to quickly: Determine exactly where the fault is Isolate the rest of the network from the failure so that it

can continue to function without interference Reconfigure or modify the network to minimize the effect

of removing the failed component(s) Repair or replace the failed components to restore the

network to its initial state


Accounting Management Reasons for accounting management:

Internal chargebacks on network use User(s) may be abusing access privileges and burdening the

network at the expense of other users Users may be making inefficient use of the network, and the

network The network manager is in a better position to plan for

network growth if user activity is known in sufficient detail.


Configuration Management

Concerned with: initializing a network and grace-fully shutting down part

or all of the network maintaining, adding, and updating the relationships

among components and the status of components themselves during network operation


Performance Management Issues of concern to the network manager include:

What is the level of capacity utilization? Is there excessive traffic? Has throughput been reduced to unacceptable levels? Are there bottlenecks? Is response time increasing?

Network managers need performance statistics to help them plan, manage, and maintain large networks


Security Management

Concerned with generating, distributing, and storing encryption keys monitoring and controlling access to networks access to all or part of the network management

information collection, storage, and examination of audit records and

security logs


Network Management Systems

Collection of tools for network monitoring and control, integrated in these ways: A single user-friendly operator interface for performing

most or all network management tasks A minimal amount of separate equipment

consists of incremental hardware and software additions implemented among existing network components


Network Management System Architecture


Components of the NMS

All nodes run the Network Management Entity (NME) software

Network control host or manager runs the Network Management Application (NMA)

Other nodes are considered agents


Network Management Entity Collection of software contained in each network node,

devoted to the network management task Performs the following tasks:

Collect statistics on communications and network-related activities.

Store statistics locally Respond to commands from the network control center Send messages to NCC when local conditions undergo a

significant change


IBM Network Management Architecture and NetView

Associated with IBM’s Systems Network Architecture (SNA)

IBM wants to provide the single, unifying framework into which all other network management products feed and from which all the equipment in a user’s network can be controlled


Network Management Categories

SNA network management is composed of: Problem management Change management Configuration management Performance and accounting management


Problem Management

Problem determination Problem diagnosis Problem bypass and recovery Problem resolution Problem tracking and control


Change Management

Software change control Microcode change control Hardware change control


Configuration Management

Physical/logical resource identification Resource relationship identification


Performance & Accounting Management

Response-time monitoring Availability monitoring Utilization monitoring Component delay monitoring Performance tuning Performance tracking and control Accounting


NetView Software Control facility

Provides the capability to operate the network.

Hardware monitor collects notifications of failures or

significant events

Session monitor Collects session-related

information on logical components of the network; includes measurements of data on response time, session failure

Status monitor Displays status information;

reactivates network resources following failures

Help facilities Descriptions of fields on

displays, and a systematic problem-solving facility

Customization facilities: Permits a user to tailor NetView


Technical Control Automatic and remote testing and monitoring of the

system, to reduce downtime due to the need to locate service personnel

Restoring and/or reconfiguring the system upon failure in real time

Providing network performance and functioning statistics to facilitate planning and management for high availability


Component-Level Technical Control

Line Monitors Captures the signal between a host system and the

network Generally employed only on the network end

Protocol Analyzers Can also simulate various network components Can test communication protocols and codes Typically handles up to layer 3 of the OSI architecture


Network Technical Control Systems Integrate control devices and centralize the control of the network


Performance Monitoring

After availability, the second most important characteristic of a network is performance

Performance data must be available in sufficient detail to be able to assess the bottleneck that is causing the problem and to plan appropriate remedial action


Component-Level Monitoring Response-time monitors

Measures, displays, and records response time of each transaction and the average response time

Hardware monitors Events: Number of occurrences of specific events Timing: Timing the duration of a specific signal

Software monitors Gathers and reports statistics on hardware and systems and

applications software activity


Network Monitoring Systems


Indicators Reported by Network Monitors

Service Parameters Availability Response Time Accuracy and Integrity

Efficiency Parameters Througput Polling Utilization


Simple Network ManagementProtocol (SNMP)

Network Management Model Management station Management agent Management information base Network management protocol


Role of SNMP


Protocol Specification

Transmission of a message Receipt of a message Variable bindings


SNMPv2

Released in 1992, revised in 1996 Addressed functional deficiencies in SNMP Accommodates decentralized network management Improves efficiency of data transfer


SNMPv3

Released in 1998, addressed security deficiencies in SNMP and SNMPv2

Does not provide a complete SNMP capability; defines an overall SNMP architecture and a set of security capabilities for use with SNMPv2

Provides three important services: authentication, privacy, and access control

chapter 19: network management

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