DC Lec 7 (Network Models)

8/3/2019 DC Lec 7 (Network Models)

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DATACOMMUNICATION

LECTURELECTURE--77


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RECAP OF LECTURE 6

Protocols

Elements of Protocols

Standards

De-Jure

De-Facto


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OVERVIEW OF LECTURE 7

Roles of Computer in Network

Peer

Client

Server

Network Models Peer to Peer (Workgroup)

Server Based (Domain Environment)


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ROLE OF COMPUTERS IN NETWORK

There are three roles of computer in a Local

Area Network

Clients

Peers

Servers.


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(CONT.) Clients

A computer is called a client in a LAN if it containsfollowing characteristics:

It uses the network resources/services.

It must have a client operating system installedon it, e.g.Win98/NT/2000Professional/XP/Vista.

It always request server for any service.


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(CONT.)

Peers

A computer is called a peer in a LAN if it contains

following characteristics:

It provides and uses network resources. It must have a peer operating system installed

on it, e.g.

Win98/NT/2000Professional/XP/Vista.


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(CONT.) Servers

A computer is called a server in a LAN if it containsfollowing characteristics:

It provides the network resources/services.

It must have server operating system installed on it,e.g. Win NT 4 Server/2000 server/2003 Server/2008server.

It accepts the requests of clients.


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NETWORK MODELS


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NETWORK MODELS

Three main types of Network Models

Peer to Peer Network

Server-Based Network

Hybrid Network


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PEER TO PEER NETWORK

(WORKGROUP)

No server No client

Every computer is a Peer Peer is the computer, which both uses and provides network resources.

No central login process

little security control

Uses Sharing disk space and resources such as printer and faxes.

Operating Systems Used

Win 98/2000 Professional/XP/Vista


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PEER TO PEER NETWORK (CONT.)

WORKGROUP

Workgroup is a group name given to a set of

computers that are logically and physically connected

together within a peer-to-peer network to share

resources. Recommended number of computers is 10.


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ADVANTAGES:

No extra investment in serverhardware and software isrequired.

Easy setup.

No network administrator is required.

Ability of users to control resources sharing. No reliance on other computer for their operation.

Lower cost for small network.


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DISADVANTAGES:

Additional load on computers because of resources sharing.

Inability of peers to handle as many networks connection as

server.

Lack of central organization, which make data hard to find.

Weak security.

Lack of central management, which makes large peer network

hard to work with.

Extra cost on training th

e users in order to manage resources.


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SERVER-BASED NETWORK

Defined by the presence of servers on a network that

provide security and administration of the network.

Server-Based or Client-Server networks divide

processing tasks between clients and servers.

Clients request services such as file storage and

printing, and servers deliver them.

Server computers typically are most powerful thanclient computer.

Minimum limit of clients and servers is 1 and

maximum limit depends on different factors.

This network is managed with respect to domain.


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SERVER-BASED NETWORK (CONT.)

DOMAIN

group name given to a set of computers that are logically andphysically connected together within a server-based network.

Domain security and logon permissions are controlled byspecial servers called domain controllers.

There is one master domain controller in each domain, calledPrimary Domain Controller (PDC), which may be assisted bysecondary domain controllers, called Backup DomainControllers (BDC).


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SERVER-BASED NETWORK (CONT.)

ADVANTAGES:

Strong central security. Central file storage, which allows all users to work from the

same set of data and provides easy backup of critical data.

Ability to share expensive equipment, such as laser printers.

Freeing of users from the tasks of managing the sharing theresources.

Easy manageability of a large number of users.

Central organization, which keeps data from getting lost amongcomputers.


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SERVER-BASED NETWORK

(CONT.)

DISADVANTAGES

Expensive dedicated hardware for servers.

Expensive network operating system software and client

licenses.

A dedicate network administrator (usually required).


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HYBRID NETWORK

Contains all three types of computers operating on Servers

Clients

Peers.

It generally has active domains and workgroups. This

means that while most shared resources are located

on servers, network users stillh

ave access to anyresources being shared by peers in workgroup. It also

means network users do not have to log on to the

domain controller to access workgroups resources

being sh

ared by peers.


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HYBRID NETWORK (CONT.)

ADVANTAGES

Hybrid networks provide the advantages of server-

based network and many of the advantages of peer-to-

peer network.


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HYBRID NETWORK (CONT.)

DISADVANTAGES

Hybrid computing shares the disadvantages

of server-based networking.


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SUMMARY

Network Model

Peer to Peer Network

Server-Based Network

Hybrid Network

DC Lec 7 (Network Models)

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