3 computer networking

8/7/2019 3 Computer Networking

1/18

COMPUTERCOMPUTER

NETWORKINGNETWORKINGBYBY

NIHAL MOHAMMADINIHAL MOHAMMADI


2/18

INTRODUCTIONINTRODUCTION

ComputerComputer networkingnetworking isis thethe jobjob ofof connectingconnecting twotwo orormoremore computerscomputers soso thatthat theythey cancan communicatecommunicate withwith

eacheach otherother andand inin turnturn permitpermit thethe user user of of thesethese

machinesmachines toto communicate,communicate, shareshare resourcesresources andand widenwiden

theirtheir reachreach beyondbeyond thethe immediatelyimmediately accessedaccessed machinemachine.. AA microcomputermicrocomputer attachedattached toto aa supersuper computer,computer, aa setset

ofof microcomputersmicrocomputers connectedconnected asas aa networknetwork oror aa setset ofof

microcomputersmicrocomputers andand aa mainframemainframe computercomputer connectedconnected

overover aa networknetwork areare allall computercomputer networksnetworks.. InIn aa sense,sense, computercomputer networksnetworks representrepresent aa peer peer--toto--

peerpeer communicationcommunication thoughthough theythey maymay havehave varyingvarying

powerpower..


3/18

WhyWhy networknetwork computers?computers?

TheThe majormajor aimaim ofof networkingnetworking computerscomputers isis toto

enableenable resourceresource sharingsharing..

FromF

rom MISMIS pointpoint ofof view,view, thethe mostmost importantimportantresourceresource sharingsharing isis datadata sharingsharing..

ProgramProgram sharingsharingisis thethe nextnext importantimportant issueissue..

PrinterPrinter sharingsharing,, whichwhich includesincludes expensiveexpensive andand

delicatedelicate equipmentequipment suchsuch asas highhigh speedspeed andand highhigh

qualityquality printer,printer, maymay bebe anotheranother importantimportant

resourceresource toto bebe sharedshared overover thethe networknetwork..


4/18

ContdContd

Networks permit collaborative working andNetworks permit collaborative working and

cooperative working between the units.cooperative working between the units.

Computer networks allowComputer networks allow people networkingpeople networkingwhich is very important for the health of thewhich is very important for the health of the

organisation.organisation.

Computer networks also permit applicationComputer networks also permit application

integration.integration.


5/18

HowHow dodo youyou networknetwork computers?computers?

1.1. LocalLocal AreaArea NetworkNetwork (LAN)(LAN)-- ComputersComputers

thatthat areare spreadspread overover aa smallsmall geographicalgeographical

areaarea areare saidsaid toto bebe connectedconnected overover aa LANLAN..

TypicalTypical characteristicscharacteristics ofof LANLAN areare::

WiredWired physicalphysical connectionconnection betweenbetween thethe

individualindividual machinesmachines..

HighHigh speedspeed connectionsconnections ofof 1010MbpsMbps--1515MbpsMbpswithwith veryvery fastfast responseresponse timestimes..


6/18

2.2. Wide Area Network (WAN)Wide Area Network (WAN)--Computers thatComputers that

are distributed over a much larger area are saidare distributed over a much larger area are saidto be connected over WAN.to be connected over WAN.

Typically , the computers spread over a townTypically , the computers spread over a town

or a city, state or a country, qualify as a WAN.or a city, state or a country, qualify as a WAN.

Because of its spread, WANs are unlikely toBecause of its spread, WANs are unlikely to

have dedicated physical connection.have dedicated physical connection.

The connections are established as and whenThe connections are established as and when

needed, and disconnected soon after use. In aneeded, and disconnected soon after use. In a

way, the users share the physical network on away, the users share the physical network on a

needneed--based sharing.based sharing.


7/18

Topology of Computer NetworksTopology of Computer Networks

TheThe networknetwork cancan bebe characterisedcharacterised throughthrough aa

setset of of attributesattributes.. TopologyTopology refersrefers toto thethe wayway

thethe computerscomputers areare physicallyphysically connectedconnected.. TheTheconnectionsconnections cancan bebe inin thethe formform ofof ring,ring, star,star,

busbus oror aa mixmix ofof thesethese..


8/18

HUB

PC1 PC2

PC4PC3

StarNetwork

PC1 PC3

PC4PC2

Bus Network

Topology of computer networks


9/18

Contd..Contd..

Star network: Is easy to operate and manages withStar network: Is easy to operate and manages with

simple cabling plans; yet it suffers from the fact thatsimple cabling plans; yet it suffers from the fact that

the center of the star can get overloaded and lead to athe center of the star can get overloaded and lead to a

critical situation.critical situation.

Ring network: can improve the performance withoutRing network: can improve the performance withoutloading a central node and is better from cablingloading a central node and is better from cabling

point of view.point of view.

Bus topology: is a common topology, especiallyBus topology: is a common topology, especially

among Ethernet LANs that permit easy growth andamong Ethernet LANs that permit easy growth andgraceful degradation of the network.graceful degradation of the network.

MediaMedia--coaxial cable, twisted pair, fiber optic cablecoaxial cable, twisted pair, fiber optic cable

and even wireless transmission.and even wireless transmission.


10/18

ProtocolsProtocols

Protocols: refers to the set of procedures that must beProtocols: refers to the set of procedures that must befollowed so that the two communicating agents canfollowed so that the two communicating agents canperform their exchange in an orderly manner.perform their exchange in an orderly manner.

Serial communication protocol is common in theSerial communication protocol is common in thecommunication between terminals and computers.communication between terminals and computers.

EIA RS232C standard is one of the most commonEIA RS232C standard is one of the most commonserial communication protocols, also the commonserial communication protocols, also the common

protocol between computers and printers.protocol between computers and printers. Centronics parallel interface is the standard forCentronics parallel interface is the standard for

parallel communication.parallel communication.


11/18

Network architectureNetwork architecture

ISO/OSI model (Open SystemISO/OSI model (Open System

Interconnection)Interconnection)

Lower layerLower layer physical characteristicsphysical characteristics

Top layerTop layer--logical characteristicslogical characteristics

Layer 1: physical connection issuesLayer 1: physical connection issues

Layer2: Concerned with the way informationLayer2: Concerned with the way information

in the form of bits and bytes are packaged forin the form of bits and bytes are packaged for

the transmission over the media.the transmission over the media.


12/18

Application Layer 7

Presentation Layer 6

Session Layer 5

Transport Layer 4

Network Layer 3

Data Link Layer 2

Physical Layer 1

PHYSICAL

LOGICAL

Seven Layered OSI Architecture


13/18

Contd..Contd..

Layer 3: deals with the nature of theLayer 3: deals with the nature of thenetworking.networking.

Layer 4: is concerned with connectivity acrossLayer 4: is concerned with connectivity across

the network including the addressing issues,the network including the addressing issues,packet assembling and disassembling.packet assembling and disassembling.

Layer 5: focuses on the quality and otherLayer 5: focuses on the quality and other

management issues.management issues. Layer 6 and 7: the way the packet interfaceLayer 6 and 7: the way the packet interface

with an application presentation and end use.with an application presentation and end use.


14/18

Network EvolutionNetwork Evolution

19601960--Defence Advanced Research ProjectDefence Advanced Research ProjectAgency (DARPA)Agency (DARPA)

In 70sIn 70s ARPANETARPANET--simple systems ofsimple systems ofconnecting computers in remote locationconnecting computers in remote location

Packet Switching, TCP/IPPacket Switching, TCP/IP

Telnet, FTP, Mail, LANTelnet, FTP, Mail, LAN

In 80sIn 80s networking of network i.e. ,networking of network i.e. ,internetworking and IP addressing schemeinternetworking and IP addressing scheme


15/18

Packet SwitchingPacket Switching

The information is broken into packets withThe information is broken into packets with

sufficient headers to identify the destination sosufficient headers to identify the destination so

that any number of intelligent agentsthat any number of intelligent agents--computer, network hubs, network interfacecomputer, network hubs, network interface

units etc. can forward them ultimately tounits etc. can forward them ultimately to

destination.destination.


16/18

Network ComponentsNetwork Components

Interface card (NIC), Access Unit InterfaceInterface card (NIC), Access Unit Interface(AUI), cable that connects card to the interface(AUI), cable that connects card to the interface

and special connector that sits on the cable thatand special connector that sits on the cable that

receives and transmitsreceives and transmits-- transceivertransceiver..

Network Cable

PC with

Network OS

NIC

AUI Cable

Transceiver


17/18

ConclusionConclusion

TheThe areaarea ofof computercomputer communicationscommunications andand

networkingnetworking isis witnessingwitnessing unprecedentedunprecedented

technologytechnology developmentsdevelopments whichwhich areare ofof suchsuchparamountparamount importanceimportance thatthat anyany managermanager

todaytoday mustmust keepkeep pacepace withwith thethe developmentsdevelopments

andand exploitexploit thethe potentialpotential forfor profitprofit..


18/18

Thank YouThank You

3 computer networking

Documents