Chapter 14

Managerial issues in networking

2

Overview

• Network design• Network management

– Hardware– Software

• Technology standards• Role of government and legal process

3

Network design

IntroductionNetwork

managementStandardization

Government and law

Introduction

• Cost containment and formal design not critical for typical home network

• Large networks need formal methods for design and management– To contain costs while meeting user needs– Standard designs and practices have been

developed in the industry based on experience

4

Network design

IntroductionNetwork

managementStandardization

Government and law

Network design

• Formal design process is useful

• Successful design ensures that

• Basic systems analysis and design principles can be adapted to network design

5

Network design

IntroductionNetwork

managementStandardization

Government and law

Requirements analysis

• Fortunately modern network technologies meet most typical user needs

• Some pockets of intense use may exist

6

Network design

IntroductionNetwork

managementStandardization

Government and law

Logical network design

• Based on user input and prior experience, requirements analysis identifies network needs

• Logical network design represents network requirements in a form that

• Drawing is a very good idea

7

Network design

IntroductionNetwork

managementStandardization

Government and law

Logical network design

• Should show for every area of the network– Total number of general-purpose desktops– Shared devices such as printers– Devices with special network needs, e.g servers– Subnets

– Network services such as DNS, DHCP– Network security and management utilities such

as firewalls

8

Network design

IntroductionNetwork

managementStandardization

Government and law

Logical network design example

• Consider an example of a small business specializing in video production– Editing group needs high bandwidth connectivity

to its storage network– Other groups only need plain desktop connectivity

• IT• Administration

– Extra network ports provisioned in every subnet for future expansion

9

Network design

IntroductionNetwork

managementStandardization

Government and law

Logical network design example

Executive offices4 corporate desktops

8 ports – 100 mbps eachSubnet: 192.168.1.0/24

Data centerStorage area network

Internal portal, DNS, DHCP, firewallNetwork equipment rack

2 ports – 1 gbps eachInternet connection – 10/ 2 mbps

Subnet: 192.168.4.0/23

IT4 desktops

1 n/w printer8 ports –

100 mbps eachSubnet:

192.168.6.0/24Admin office15 corporate desktops

1 network printer20 ports – 100 mbps each

Subnet: 192.168.2.0/24

Editing room20 workstations1 network printer30 ports – 1 gbps

eachSubnet: 192.168.3.0

/24

10

Network design

IntroductionNetwork

managementStandardization

Government and law

Physical network design

• Logical design reviewed by IT and end users

• Physical network design indicates the technologies that will be used to implement the logical design

11

Network design

IntroductionNetwork

managementStandardization

Government and law

Physical network design example

Cisco 3600SERIES

0 1

READY

ACTIVE

2 4

COM AUX

PCMCIA

1

0SYSTEM RPSExecutive offices

Data center

IT

Admin office

Editing room

Internet

SAN

executive offices Ethernet

admin offices Ethernetvideo editors

Ethernet

IT Ethernet

To servers

1 gbps

100 mbps

WAN link

Legend

12

Network design

IntroductionNetwork

managementStandardization

Government and law

Implementation

• Networks in young organizations often use best-of-breed

• As organizations mature, designs are often implemented using a common set of technologies

• Design in example could also have used 1 gbps Ethernet ports throughout the company

13

Network design

IntroductionNetwork

managementStandardization

Government and law

Campus network

• Computer networks typically fall into three categories– Building networks

• Smallest network unit• Design standardized from experience

– Campus networks• Span multiple buildings in close vicinity• Typical state university

– Enterprise networks• Network scattered across campuses• Uses WAN technologies

14

Network design

IntroductionNetwork

managementStandardization

Government and law

Campus network example

VCC OK

SYSTEM

ALARM250V~5A

30V 5A

1

0

PCMCIA

CISCO3660-MB-2FE

NO NCP

CONSOLE AUX

R

10/100 ETHERNET 0/0

FDXLINK100Mbps

10/100 ETHERNET 0/1

FDXLINK

100Mbps

Core 1

VCC OK

SYSTEM

ALARM250V~5A

30V 5A

1

0

PCMCIA

CISCO3660-MB-2FE

NO NCP

CONSOLE AUX

R

10/100 ETHERNET 0/0

FDXLINK100Mbps

10/100 ETHERNET 0/1

FDXLINK

100Mbps

Core 2

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

Business

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

Eng

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

Admin

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

Health

A&S

Eng

IT

SACEdu

Bsn

HospNurs

1 gbps access layer

1 gbps distribution layer

10 gbps core layer

Legend

10 gbps

1 gbps

100 mbps

Internet

15

Network design

IntroductionNetwork

managementStandardization

Government and law

Campus networks

• Typically have three layers– Core layer– Distribution layer– Access layer

• Core layer– Optimized for fast packet handling and availability– Routers only responsible for forwarding to

appropriate distribution layer device

16

Network design

IntroductionNetwork

managementStandardization

Government and law

Campus networks

• Distribution layer– Organizes network into subnets– Handles routing– Implements administrative policies using firewall etc– Can offer network services such as DNS, DHCP– Handles Internet connection

• Access layer– Provides network ports to end users– Can offer network services such as DNS, DHCP– Typically uses building network architecture

17

Network design

IntroductionNetwork

managementStandardization

Government and law

Enterprise networks

• Successful organizations add offices in other cities, states and countries

• Campuses need to be connected to each other using WAN technologies

• Some campuses could be small

18

Network design

IntroductionNetwork

managementStandardization

Government and law

Enterprise networks

V C C O K

S Y S T E M

ALARM2 5 0 V ~ 5 A

3 0 V 5 A

1

0

P C M C IA

CISCO3660-MB-2FE

N O N CP

C O N S O L E A U X

R

1 0 /1 0 0 E T H E R N E T 0 /0

F D X

L IN K

1 0 0 M b p s

1 0 /1 0 0 E T H E R N E T 0 /1

F D X

L IN K

1 0 0 M b p s

V C C O K

S Y S T E M

ALARM2 5 0 V ~ 5 A

3 0 V 5 A

1

0

P C M C IA

CISCO3660-MB-2FE

N O N CP

C O N S O L E A U X

R

1 0 /1 0 0 E T H E R N E T 0 /0

F D X

L IN K

1 0 0 M b p s

1 0 /1 0 0 E T H E R N E T 0 /1

F D X

L IN K

1 0 0 M b p s

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

V C C O K

S Y S T E M

ALARM2 5 0 V ~ 5 A

3 0 V 5 A

1

0

P C M C IA

CISCO3660-MB-2FE

N O N CP

C O N S O L E A U X

R

1 0 /1 0 0 E T H E R N E T 0 /0

F D X

L IN K

1 0 0 M b p s

1 0 /1 0 0 E T H E R N E T 0 /1

F D X

L IN K

1 0 0 M b p s

V C C O K

S Y S T E M

ALARM2 5 0 V ~ 5 A

3 0 V 5 A

1

0

P C M C IA

CISCO3660-MB-2FE

N O N CP

C O N S O L E A U X

R

1 0 /1 0 0 E T H E R N E T 0 /0

F D X

L IN K

1 0 0 M b p s

1 0 /1 0 0 E T H E R N E T 0 /1

F D X

L IN K

1 0 0 M b p s

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

AUX

ACT

LINK

100 Mbps

FASTETHERNET 0/0 CONSOLE

W1 W0

Cisco 3631

WAN

19

Network design

IntroductionNetwork

managementStandardization

Government and law

Network maintenance

• Networks need ongoing maintenance for performance– activities performed to keep networks in a

serviceable condition or to restore them to serviceability

– Includes activities such as inspection, testing, and servicing

• Two categories of assets– Hardware– Software

20

Network design

IntroductionNetwork

managementStandardization

Government and law

Hardware maintenance

• Typical network may have hundreds of devices• Manual monitoring is very expensive

• Two components– Management station

– Network agents

21

Network design

IntroductionNetwork

managementStandardization

Government and law

Network management with SNMP

Network management station

Managed devices running

management agents

SNMP used to read and write to MIB on managed devices

PCs with agentsSwitches with agents

22

Network design

IntroductionNetwork

managementStandardization

Government and law

Hardware maintenance

• Network agents store information about their device in a management information base (MIB)– MIB only contains information necessary for

• fault management or • configuration management

• Management station uses SNMP protocol to set or retrieve values from the MIB

23

Network design

IntroductionNetwork

managementStandardization

Government and law

Software maintenance

• One of the biggest concerns in software maintenance is patching

• Tools have been developed to automatically scan all networked software on every device on the network– Confirm application of patches and other utilities– Nessus is a popular free tool

24

Network design

IntroductionNetwork

managementStandardization

Government and law

Nessus scan

25

Network design

IntroductionNetwork

managementStandardization

Government and law

Standards

• Communication on the Internet almost always works

• Compare smooth connectivity on the Internet to other environments

26

Network design

IntroductionNetwork

managementStandardization

Government and law

Standards

• Most technologies used on the Internet follow standards– documents, established by consensus and

approved by a recognized body that help achieve high degree of order

– Products that comply with standards can easily inter-operate with other devices compliant with the same standard

• TCP/ IP, Ethernet are standards

27

Network design

IntroductionNetwork

managementStandardization

Government and law

Standards creation

• Typically follows well-established procedure– Expert organization takes lead

• Develops requirements for the new standard– Meet communication needs that can be economically satisfied with

available technology

– Technology solutions are proposed by interested organizations

– Proposed solutions are evaluated– Solution with overwhelming majority becomes

standard• E.g. development of IEEE 802.11n standard

28

Network design

IntroductionNetwork

managementStandardization

Government and law

Government involvement

• Technological development is mostly led by private sector

• However, government has played a key role in the development of networking technologies– Packetization by Department of Defense– Early Internet by National Science Foundation– Web browser by National Science Foundation– Allocation of wireless spectrum by the FCC

29

Network design

IntroductionNetwork

managementStandardization

Government and law

Legal process

• Development of the phone network was influenced by judicial and legislative actions– Modified final judgment (1982) introduced

competition in long distance phone service• Judicial action

– Telecommunications act of 1996 introduced competition in local phone service

• Legislative action

• Net neutrality debate is ongoing

Summary

• Formal network design process helps networks meet end user requirements most effectively

• Automated network maintenance is important to keep large networks operational

• Standards enable inter-operability of communication equipment

• Government and legal process have played critical roles in helping the evolution of communication technologies

Case study

• Telework and telecommuting– Networks are changing how we work– Over 20% of the US workforce telecommutes

• Networks bring resources to places where they would otherwise be unavailable– Haiti earthquake, Jan 12, 2010– Ongoing medical care

• Local specialists access the expertise of physicians in Miami and other places

Hands-on exercise

• OPNET LAN project

Network design

• Wanted ad