WHAT IS NETWORKING?WHAT IS NETWORKING?

NETWORKING SIMPLY MEANS NETWORKING SIMPLY MEANS THE THE CONNECTION BETWEEN TWO OR MORE CONNECTION BETWEEN TWO OR MORE

COMPUTERS.COMPUTERS. A NETWORK PROVIDES THE A NETWORK PROVIDES THE SHARING OF HARDWARE.SHARING OF HARDWARE.

WE NEED NETWORKWE NEED NETWORK IN ADDITION TO THE IN ADDITION TO THE SPEED AND RELIABILITY OF DATA TRANFER SPEED AND RELIABILITY OF DATA TRANFER

COMPUTERS.COMPUTERS.IT ALLOWS A FLEXIBLE WORK ENVIRONMENT IT ALLOWS A FLEXIBLE WORK ENVIRONMENT

MAINLY BECAUSE THEY ALLOW REMOTE MAINLY BECAUSE THEY ALLOW REMOTE ACCESS TO RESOURSE AT WORKPLACE.ACCESS TO RESOURSE AT WORKPLACE.

TYPES OF NETWORKINGTYPES OF NETWORKING..

##LAN :-LOCAL AREA NETWORKLAN :-LOCAL AREA NETWORK A LAN CONTAINS A LIMITED NUMBERS OF COMPUTERS AND CAN A LAN CONTAINS A LIMITED NUMBERS OF COMPUTERS AND CAN

COVER A SMALL DISTANCE.COVER A SMALL DISTANCE.EX:-DEPARTMENTAL STOREEX:-DEPARTMENTAL STORE..

##MAN:-METRPOLITAN AREA NETWORKMAN:-METRPOLITAN AREA NETWORK IT COVERS A MUCH AREA THAN LAN IN A METROPOLITAN CITY.IT COVERS A MUCH AREA THAN LAN IN A METROPOLITAN CITY.

EX:-CAMPUS NETWORKEX:-CAMPUS NETWORK

#WAN:-WIDE AREA NETWORK#WAN:-WIDE AREA NETWORK A WAN SPREAD OVER DIFFERENT CITIES & TOWNS A WAN SPREAD OVER DIFFERENT CITIES & TOWNS EX:-INTERNETEX:-INTERNET

COMPUTER NETORKING COMPUTER NETORKING DEVICES.DEVICES.

COMPUTER NETWORKING DEVICE ARE UNITS THAT ARE COMPUTER NETWORKING DEVICE ARE UNITS THAT ARE MEDIATE DATA IN A COMPUTER NETWORK .THIS DEVICES MEDIATE DATA IN A COMPUTER NETWORK .THIS DEVICES ARE ALSO CALLED NETWORK EQUIPMENTS . ARE ALSO CALLED NETWORK EQUIPMENTS .

MAIN NETWORKING DEVICESMAIN NETWORKING DEVICES#HUB#HUB#BRIDGES#BRIDGES#REPEATER #REPEATER #ROUTER#ROUTER#SWITCH#SWITCH#NETWORK INTERFACE CARD(NIC)#NETWORK INTERFACE CARD(NIC)#CABLES#CABLES#FIREWALLS#FIREWALLS

HUBHUB

**A CENTRAL POINT OF A STAR TOPOLOGIESA CENTRAL POINT OF A STAR TOPOLOGIES

**CAN BE MORE THAN A BASIC HUB –PROVIDING CAN BE MORE THAN A BASIC HUB –PROVIDING ADDITIONAL SERVICES ADDITIONAL SERVICES

**ALLOWS THE MULTIPLE CONNECTION OF DEVICE ALLOWS THE MULTIPLE CONNECTION OF DEVICE

**IN REALITY A HUB IS A REAPETER WITH MULTIPLE PORTS IN REALITY A HUB IS A REAPETER WITH MULTIPLE PORTS

**FUNCTION IN SIMILAR MANNER TO A REPEATERFUNCTION IN SIMILAR MANNER TO A REPEATER

**WORKS AT THE PHYSICAL LAYER OF OSI MODELWORKS AT THE PHYSICAL LAYER OF OSI MODEL

**USE LARGE HUBS OF 24 PORTS OR STACKING THEM IS AUSE LARGE HUBS OF 24 PORTS OR STACKING THEM IS A NEGATIVE FEATURE.NEGATIVE FEATURE.

HUBHUB

THERE ARE MAINLY FOUR THERE ARE MAINLY FOUR COMPONANTS OF HUBCOMPONANTS OF HUB

• ETHERNET WIREETHERNET WIRE• NETWORK INTERFACE CARDSNETWORK INTERFACE CARDS• NETWORKING HUBS NETWORKING HUBS • NETWORKING SOFTWARENETWORKING SOFTWARE

BRIDGEBRIDGE

A BRIDGE IS A DEVICE THAT HELPS TO INTERCONNECT WIRED A BRIDGE IS A DEVICE THAT HELPS TO INTERCONNECT WIRED

LANS WITH EACH OTHER . BRIDGES ARE PART OF A SECOND LANS WITH EACH OTHER . BRIDGES ARE PART OF A SECOND LAYER OF OSI MODEL . IT GENERATES A SIGNALS AND PASSES LAYER OF OSI MODEL . IT GENERATES A SIGNALS AND PASSES IT ON. IT ON. FOR EX:- IF A DATA SIGNAL GETS CORRUPTED BEFORE REACHI-FOR EX:- IF A DATA SIGNAL GETS CORRUPTED BEFORE REACHI-ING A BRIDGE , THE BRIDGE PASSES ON THE CORRUPTED DATA ING A BRIDGE , THE BRIDGE PASSES ON THE CORRUPTED DATA

TO THE NETWORK SEGMENTS ATTACHED TO IT.TO THE NETWORK SEGMENTS ATTACHED TO IT.TRANSPERENT BRIDGES (IEEE 802.1 D) MAKE ALL ROUTING DECI-TRANSPERENT BRIDGES (IEEE 802.1 D) MAKE ALL ROUTING DECI-SION THE BRIDGES IS SAID TO BE TRANPARENT TO THE SION THE BRIDGES IS SAID TO BE TRANPARENT TO THE

WORKSTATION . THE BRIDGE WILL AUTOMATICALY INITIALISEDWORKSTATION . THE BRIDGE WILL AUTOMATICALY INITIALISED ITSELF AND CONFIGURE ITS OWN ROUTING INFORMATION AFTERITSELF AND CONFIGURE ITS OWN ROUTING INFORMATION AFTERIT HAS BEEN ENABLED.IT HAS BEEN ENABLED.IF WORKSTATION ON NETWORK SEGMENT A NEEDED ACCESS TO AIF WORKSTATION ON NETWORK SEGMENT A NEEDED ACCESS TO ASERVER,THE BEST PLACE TO LOCATE THAT SERVER IS ON THE SERVER,THE BEST PLACE TO LOCATE THAT SERVER IS ON THE

SAME SEGMENT AS WORKSTATION,AS SAME SEGMENT AS WORKSTATION,AS THIS MINIMISES TRAFFIC ON THE OTHER SEGMENT,AND AVOID THIS MINIMISES TRAFFIC ON THE OTHER SEGMENT,AND AVOID

THE DELAY INCURRED BY THE BRIDGE.THE DELAY INCURRED BY THE BRIDGE.

REPEATERREPEATER

**REPEATER CONNECT MULTIPLE NETWORK SEGMENTS TOGETHER.REPEATER CONNECT MULTIPLE NETWORK SEGMENTS TOGETHER.

**THEY AMPLIFY THE INCOMING SIGNAL RECEIVED FROM ONE THEY AMPLIFY THE INCOMING SIGNAL RECEIVED FROM ONE

SEGMENT AND SEND IT ON TO ALL OTHER ATTACHED SEGMENT AND SEND IT ON TO ALL OTHER ATTACHED SEGMENTSEGMENT

**THIS ALLOWS THE DISTANCE LIMITATIONS OF NETWORK THIS ALLOWS THE DISTANCE LIMITATIONS OF NETWORK

CABLING TO BE EXTENDED .THERE ARE NUMBER LIMITS ON CABLING TO BE EXTENDED .THERE ARE NUMBER LIMITS ON THE NUMBER OF REPEATERS WHICH CAN BE USED.THE NUMBER OF REPEATERS WHICH CAN BE USED.

**REPEATERS ALSO ALLOW ISOLATION OF SEGMENTS IN THE REPEATERS ALSO ALLOW ISOLATION OF SEGMENTS IN THE

EVENT OF FAILURES OR FUALT CONDITIONS.EVENT OF FAILURES OR FUALT CONDITIONS.

**THE NETWORK NUMBER ASSIGNED TO THE MAIN NETWORK THE NETWORK NUMBER ASSIGNED TO THE MAIN NETWORK SEGMENT AND THE NETWORK NUMBER ASIGNED TO THE SEGMENT AND THE NETWORK NUMBER ASIGNED TO THE OTHER SIDES OF THE REPEATER ARE THE SAMEOTHER SIDES OF THE REPEATER ARE THE SAME

**THE TRAFFIC GENERATED ON ONE SEGMENT IS PROPAGATED THE TRAFFIC GENERATED ON ONE SEGMENT IS PROPAGATED ONTO THE OTHER SEGMENT .THIS CAUSE A RISE IN THE ONTO THE OTHER SEGMENT .THIS CAUSE A RISE IN THE TOTAL AMOUNT OF TRAFFIC ,SO IF THE NETWORK SEGMENTS TOTAL AMOUNT OF TRAFFIC ,SO IF THE NETWORK SEGMENTS

ARE ALREADY LOADED ,ITS NOT A GOOD IDEA TO USE A ARE ALREADY LOADED ,ITS NOT A GOOD IDEA TO USE A REPEATER . REPEATER .

ROUTERROUTER

**ROUTER WORKS ON A NETWORK LAYER IN AN INTELLIGENT ROUTER WORKS ON A NETWORK LAYER IN AN INTELLIGENT

MANNER.MANNER.

**IT CAN CONNECT DIFFERENT NETWORK SEGMENTS , IF THEY IT CAN CONNECT DIFFERENT NETWORK SEGMENTS , IF THEY

ARE IN SAME BUILDING .ARE IN SAME BUILDING .

**WORKS IN LAN, MAN & WAN. USING DIFFERENT PROTOCOLS.WORKS IN LAN, MAN & WAN. USING DIFFERENT PROTOCOLS.

**ALLOWS ACCESS TO RESOURCE BY SELECTING THE BESTALLOWS ACCESS TO RESOURCE BY SELECTING THE BEST

PATHPATH• IT CAN FUNCTION AS BOTH IT CAN FUNCTION AS BOTH A BRIDGE & A ROUTER.A BRIDGE & A ROUTER.

**ROUTING TABLE:-- A DATABASE WHICH KEEPS TRACK OF THE ROUTING TABLE:-- A DATABASE WHICH KEEPS TRACK OF THE

ROUTES TO NETWORK AND THE ASSOCIATED COSTS.ROUTES TO NETWORK AND THE ASSOCIATED COSTS.

**STATIC ROUTING:-- ROUTES ARE MANUALLY CONFIGURED BY ASTATIC ROUTING:-- ROUTES ARE MANUALLY CONFIGURED BY A

NETWORK ADMINISTRATOR.NETWORK ADMINISTRATOR.

**DYNAMIC ROUTING:-- ADJUST AUTOMATIC TO THE CHANGES DYNAMIC ROUTING:-- ADJUST AUTOMATIC TO THE CHANGES

IN NETWORK TOPOLOGIES.IN NETWORK TOPOLOGIES.

ROUTER

STATIC ROUTING DYNAMIC ROUTING

SWITCHSWITCH

**SWITCHES :-- A MULTIPLE BRIDGE ,FUNCTIONING AT THE DATASWITCHES :-- A MULTIPLE BRIDGE ,FUNCTIONING AT THE DATA

LINK LAYER.LINK LAYER.

**EACH PORT OF THE BRIDGE DECIDES WHETHER TO FORWARDEACH PORT OF THE BRIDGE DECIDES WHETHER TO FORWARD

DATA PACKETS TO THE ATTACHED NETWORK.DATA PACKETS TO THE ATTACHED NETWORK.

**ACTS LIKE A HUB, BUT FILTER LIKE A BRIDGEACTS LIKE A HUB, BUT FILTER LIKE A BRIDGE

**EACH PORT ON A SWITCHES IS A COLLISION DOMAIN.EACH PORT ON A SWITCHES IS A COLLISION DOMAIN.

**CROSS-BAR SWITCHESCROSS-BAR SWITCHES:--:--

~READ THE DESTINATION ADDRESS THEN IMMEDIATELY ~READ THE DESTINATION ADDRESS THEN IMMEDIATELY FORWARDFORWARD

~ ACTS AS A SIMPLE REPEATER ONCE THE PATH IS ESTABLISH.~ ACTS AS A SIMPLE REPEATER ONCE THE PATH IS ESTABLISH.

**CELL-BACKPLANE SWITCH:--CELL-BACKPLANE SWITCH:--

~ BREAK THE FRAME INTO SMALL FIXED CELL LENGTHS.~ BREAK THE FRAME INTO SMALL FIXED CELL LENGTHS.~ THE CELLS ARE BUFFERED AT THE DESTINATION PORT.~ THE CELLS ARE BUFFERED AT THE DESTINATION PORT.

**STORE-FORWARD SWITCH:--STORE-FORWARD SWITCH:--

~THEY EXAMINE THE ENTIRE PACKETS.~THEY EXAMINE THE ENTIRE PACKETS.~DETECT MORE ERRORS THAN THE CUT-THROUGH VARIETY.~DETECT MORE ERRORS THAN THE CUT-THROUGH VARIETY.

Switch

CROSS-BAR SWITCH CELL-BACKPLANE SWITCH STORE-FORWARD SWITCH

CABLESCABLES

Cables are used to transfer the data from one Cables are used to transfer the data from one place to another place. There are three types of place to another place. There are three types of cables.cables.

Coaxial cableCoaxial cable Fiber-optical cableFiber-optical cable Twisted-pair cableTwisted-pair cable

CO-OXIAL CABLESCO-OXIAL CABLES

Coaxial cable carries signals of higher Coaxial cable carries signals of higher frequency ranges.frequency ranges.

Applications In telephone networks

Cable TV networks In traditional Ethernet LANs

FIBER-OPTICAL CABLEFIBER-OPTICAL CABLE

A Fiber optical cable is made of glass A Fiber optical cable is made of glass or plastic and transmits signals in the or plastic and transmits signals in the

form of lightform of light

Advantages Higher bandwidth

Less signal attenuationImmunity to electromagnetic

interferenceResistance to corrosive materials

Light weight

TWISTED-PAIR CABLETWISTED-PAIR CABLE

A twisted pair consists of two conductors each A twisted pair consists of two conductors each with its own plastic insulation twisted together. with its own plastic insulation twisted together. One of the wires is used to carry signals to the One of the wires is used to carry signals to the receiver and the other is used only as a ground receiver and the other is used only as a ground referencereference. .

ApplicationApplication In telephone linesIn telephone lines In local area networksIn local area networks

COMPARISIONCOMPARISION

HUB & SWITCHHUB & SWITCHTHE ROLE PLAYED BY A HUB OR SWITCH CAN BE SIMPLE ASTHE ROLE PLAYED BY A HUB OR SWITCH CAN BE SIMPLE AS

BUYING A HUB & CABLE AND PLUGGING THEM IN.BUYING A HUB & CABLE AND PLUGGING THEM IN.

HUB REQIRES ALMOST NO INSTALLATION . EACH OF COMPUTER HUB REQIRES ALMOST NO INSTALLATION . EACH OF COMPUTER

MAY STILL NEED TO BE CONFIGURED TO TALK TO THE INTERNETMAY STILL NEED TO BE CONFIGURED TO TALK TO THE INTERNET

THE DEVICES USING THEM ALL SHARE SAME BANDWIDTH.THE DEVICES USING THEM ALL SHARE SAME BANDWIDTH.

WHILEWHILE

SWITCHES DON’T FOR ALL NETWORK DEVICE TO SHARE THE SWITCHES DON’T FOR ALL NETWORK DEVICE TO SHARE THE

SAME BANDWIDTH.SAME BANDWIDTH.

WHAT IS THE DIFFERENCE?WHAT IS THE DIFFERENCE?

ROUTERS -- SWITCHES – HUBROUTERS -- SWITCHES – HUBIN A IN A HUBHUB , FRAME IS PASSED ALONG OR “BROADCAST “ TO , FRAME IS PASSED ALONG OR “BROADCAST “ TO

EVERY ONE OF ITS PORT , NO MATTER THAT THE FRAME IS ONEVERY ONE OF ITS PORT , NO MATTER THAT THE FRAME IS ON

ONLY DESTINATED TO ONE PORT.ONLY DESTINATED TO ONE PORT.

IN CASE OF IN CASE OF SWITCHSWITCH

IT KEEPS A RECORD OF THE IT KEEPS A RECORD OF THE MAC ADDRESSMAC ADDRESS OF ALL THE OF ALL THE

DEVICES CONNECTED TO IT.SO WHEN A FRAME IS RECEIVED DEVICES CONNECTED TO IT.SO WHEN A FRAME IS RECEIVED

IT KNOWS EXATLY WHICH PORT TO SEND IT.IT KNOWS EXATLY WHICH PORT TO SEND IT.

IN CASE OF IN CASE OF ROUTERROUTER

IT’S JOB IS TO ROUTE PACKETS TO OTHER NETWORKS UNTILIT’S JOB IS TO ROUTE PACKETS TO OTHER NETWORKS UNTIL

THAT PACKET ULTIMATELY REACHES ITS DESTINATION.THAT PACKET ULTIMATELY REACHES ITS DESTINATION.

ADVANTAGES & DISADVANTAGESADVANTAGES & DISADVANTAGES

HUB:-HUB:-ADVANTAGES—ADVANTAGES—

~ ~ HUB MAY BE CASCADED TO ADD ADDITIONAL PORTS.HUB MAY BE CASCADED TO ADD ADDITIONAL PORTS.

~~BECOMING A LOW COST SOLUTIONBECOMING A LOW COST SOLUTION

~~ UTILIZE EXISTING CABLING & OTHER NETWORK COMPOSITES. UTILIZE EXISTING CABLING & OTHER NETWORK COMPOSITES.

DISADVANTAGE—DISADVANTAGE—

~~CAN NOT FILTER INFORMATIONCAN NOT FILTER INFORMATION

~~EXTENDS COLLISION DOMAIN.EXTENDS COLLISION DOMAIN.

BRIDGE:-BRIDGE:-ADVANTAGES:--ADVANTAGES:--

~~INCREASE THE NUMBER OF ATTACHED WORKSTATION & INCREASE THE NUMBER OF ATTACHED WORKSTATION &

NETWORK SEGMENTS.NETWORK SEGMENTS.

~~THEY ARE TRANSPARENT TO HIGHER LEVEL PROTOCOLS DUETHEY ARE TRANSPARENT TO HIGHER LEVEL PROTOCOLS DUE

TO MAC LAYERTO MAC LAYER

DISADVANTAGES:--DISADVANTAGES:--

~~IT MAY OVERLOADED DURING PERIOD OF HIGH TRAFFIC.IT MAY OVERLOADED DURING PERIOD OF HIGH TRAFFIC.

~~THE BUFFERING OF FRAMES INTRODUCE NETWORK DELAY.THE BUFFERING OF FRAMES INTRODUCE NETWORK DELAY.

ROUTER:-ROUTER:-ADVANTAGES:--ADVANTAGES:--

~~LIMITS THE COLLISION DOMAINLIMITS THE COLLISION DOMAIN

~~CAN FUNCTION IN LAN & WANCAN FUNCTION IN LAN & WAN

~~CAN FILTER BROADCAST, DETERMINE BEST PATH.CAN FILTER BROADCAST, DETERMINE BEST PATH.

DISADVANTAGES:--DISADVANTAGES:--

~~EXPENSIVE, MUST USE ROUTABLE PROTOCOLEXPENSIVE, MUST USE ROUTABLE PROTOCOL

~~SLOWER THAN BRIDGESLOWER THAN BRIDGE

~~CAN BE DIFFICULT TO CONFIGURE.CAN BE DIFFICULT TO CONFIGURE.

SWITCH:--SWITCH:--ADVANTAGES:-ADVANTAGES:-

~~LIMITS THE COLISION DOMAINLIMITS THE COLISION DOMAIN

~~CAN IMPROVE BRIDGINGCAN IMPROVE BRIDGING

~~CAN BE CONFIGURED TO LIMIT BROADCAST DOMAINCAN BE CONFIGURED TO LIMIT BROADCAST DOMAIN

DISADVANTAGES:--DISADVANTAGES:--

~~MORE EXPENSIVE THAN A HUB OR BRIDGEMORE EXPENSIVE THAN A HUB OR BRIDGE

~~CONFIGURATION OF ADDITIONAL FUNCTION CAN BE VERY CONFIGURATION OF ADDITIONAL FUNCTION CAN BE VERY

COMPLEX.COMPLEX.

REPEATER:--REPEATER:--ADVANTAGES:--ADVANTAGES:--

~~CAN CONNECT DIFFERENT TYPES OF MEDIACAN CONNECT DIFFERENT TYPES OF MEDIA

~~CAN EXTEND A NETWORK IN TERM OF DISTANCESCAN EXTEND A NETWORK IN TERM OF DISTANCES

~~DOES NOT INCREASE NETWORK TRAFFICDOES NOT INCREASE NETWORK TRAFFIC

DISADVANTAGES:-DISADVANTAGES:-

~~EXTENDS THE COLLISION DOMAIN EXTENDS THE COLLISION DOMAIN

~~CAN NOT FILTER DATA CAN NOT FILTER DATA

~~LIMITED NUMBERS ONLY CAN BE USED IN NETWORKLIMITED NUMBERS ONLY CAN BE USED IN NETWORK

BIBLOGRAPHYBIBLOGRAPHY

BOOK REFFERED:--BOOK REFFERED:--

COMPUTER NETWORKS ( ANDREW S. TANENBAUM )COMPUTER NETWORKS ( ANDREW S. TANENBAUM )

COMPUTER NETWORKS (NIIT)COMPUTER NETWORKS (NIIT)

DATA COMMUNICATION & NETWORK ( BY FOROUZAN )DATA COMMUNICATION & NETWORK ( BY FOROUZAN )

RELATED URL’S:-RELATED URL’S:-NETGEAR.NETNETGEAR.NET

BRASSCANNON.NETBRASSCANNON.NET