INTRODUCTION TO NETWORKING DEVICES FOR BEGINNERS

INTRODUCING STUDENTS TO NETWORKING DEVICES FOR BEGINNERS

1. NETWORKING DEVICES AND CABLING
1.
NetworkInterfaceCard(NIC)
-Anetworkinterfacecard(NIC)isahardwarecomponent,
typicallyacircuitboardorchip,installedonacomputersoit
canconnecttoanetwork.
Functions Modern NICs
-NICprovidesthelinkbetweenyourcomputerandyour
network.Itprovidesthephysicalconnectionbetweenthe
networkandtheworkstation
-NICprovidesthephysicalconnectionbetweenmachineand
medium.Itcontrolsthehost’saccesstothemedium
-NICtranslatestheparallelsignalsproducedbythecomputer
intoserialformatthatissentoverthenetwork
LECTURE 4

2. Fig. Network Interface Card (NIC)

3. 2.Repeater

Repeatersaredefinedasanetworkingdevicethatisusedtoamplify
andgeneratetheincomingsignal.Repeatersworkatthephysicallayer
oftheOSImodel.Themainaimofusingarepeateristoincreasethe
networkingdistancebyincreasingthestrengthandqualityofsignals.
TheperformanceofLocalAreaNetworks(LANs)andWideArea
Networks(WANs)repeatersareused.Usingrepeatershelpstoreduce
error,andlossofdataandprovideswithdeliveryofdataatspecified
locationsonly.Themajoradvantageofusingarepeateristhatit
provideswithtransferofdatawithmoresecurityandoveralong
distance

4. 3.Hub

Ahubisabasicallymulti-portrepeater.Ahubconnects
multiplewirescomingfromdifferentbranches,for
example,theconnectorinstartopologywhichconnects
differentstations.Hubscannotfilterdata,sodatapackets
aresenttoallconnecteddevices.Inotherwords,the
collisiondomainofallhostsconnectedthroughHub
remainsone.Also,theydonothavetheintelligenceto
findoutthebestpathfordatapacketswhichleadsto
inefficienciesandwastage.

5. 4.Bridge

Abridgeoperatesatthedatalinklayer.Abridgeisa
repeater,withaddonthefunctionalityoffilteringcontent
byreadingtheMACaddressesofthesourceand
destination.ItisalsousedforinterconnectingtwoLANs
workingonthesameprotocol.Ithasasingleinputand
singleoutputport,thusmakingita2portdevice.
Bridges perform three main functions:
■They learn where devices are located by placing the MAC
address of a NIC and the identifier of the bridge port to
which it is connected in a port address table.
■They forward traffic intelligently, drawing on information
they have in their port address table.
■They remove layer 2 loops by running the Spanning Tree
Protocol (STP).

6. 4. Switch

Switchisahighspeedmulti-portbridge.Switches,
likebridges,operateatthedatalinklayer.Thethree
mainfunctionsofabridgearealsotrueofaswitch:
theylearn,forward,andremoveloops.However,
switcheshavemanymorefeaturesthanbridges;for
instance,theymaketheirswitchingdecisionsin
hardwarebyusingapplication-specificintegrated
circuits(ASICs).ASICsarespecializedprocessorsbuilt
toperformveryfewspecifictasks.Becausetheydo
onlyafewthings,ASICsaremuchmorecost-effective
thanagenericprocessor,suchastheoneinyourPC.
Cisco,likemostnetworkingvendors,extensivelyuses
ASICsthroughoutitsswitchingproducts.

7. 5.Router

A router is a device like a switch that routes data packets
based on their IP addresses.

The router is mainly a Network Layer device.

Routers normally connect LANs and WANs and have a
dynamically updating routing table based on which they
make decisions on routing the data packets.

The router divides the broadcast domains of hosts
connected through it

8. Diagram

9. 6.Gateway

Gateway is a network point that acts as an entrance to another network.
Essentially a gateway is normally a computer that operates in all layers of
the OSI model

A gateway, as the name suggests, is a passage to connect two networks that
may work upon different networking models.

They work as messenger agents that take data from one system, interpret it,
and transfer it to another system.

Gateways are also called protocol converters and can operate at any
network layer.

Gateways are generally more complex than switches or routers.

A gateway is also called a protocol converter.

10. Note..

Hubscannotsolvebandwidthorcollisionproblems.

Bridgesandswitches,ontheotherhand,can.

Bridgesandswitchestakeonelargecollisiondomainand
splititintoabunchofsmallerones.

Inthissense,theycreateextracollisiondomains,since
eachinterfaceofthelayer2deviceisaseparatecollision
domain.Thisprocessiscalledmicrosegmentation.

Routers,atthenetworklayer,canalsosolvecollision
problems,buttheycostmorethanbridgesorswitches

11. EXPERIMENT 1 PART 1
Network Cable Types and Specifications
,
There are three types of network cables;
a) coaxial,
b) twisted-pair, and
c) fiber-optic
To connect two or more computers or networking devices in a network
network cables are used
a)Coaxialcable
Thiscablecontainsaconductor,insulator,braiding,andsheath.
The sheath covers the braiding, braiding covers the insulation, and the insulation
covers the conductor.
ComponentsofCoaxialcable

12. ComponentsofCoaxialcable
Sheath
This is the outer layer of the coaxial cable. It protects the cable from physical
damage.
Braided-shield
This shield protects signals from external interference and noise. This shield is
built from the same metal that is used to build the core.
Insulation
Insulationprotectsthecore.Italsokeepsthecoreseparatefromthebraided-
shield.Sinceboththecoreandthebraided-shieldusethesamemetal,without
thislayer,theywilltoucheachotherandcreateashort-circuitinthewire.
Conductor
The conductor carries electromagnetic signals. Based on conductor a coaxial
cable can be categorized into two types; single-core coaxial cable and multi-
core coaxial cable.

13. A single-core coaxial cable uses a single central metal (usually copper)
conductor,
while a multi-core coaxial cable uses multiple thin strands of metal wires.
The following image shows both types of cable.

14. Coaxial cables in computer networks
Thecoaxialcableswerenotprimarilydevelopedforthecomputernetwork.These
cablesweredevelopedforgeneralpurposes.Theywereinuseevenbefore
computernetworkscameintoexistence.Theyarestillusedeventheirusein
computernetworkshasbeencompletelydiscontinued.
Atthebeginningofcomputernetworking,whentherewerenodedicatedmedia
cablesavailableforcomputernetworks,networkadministratorsbeganusing
coaxialcablestobuildcomputernetworks.
Becauseoflow-costandlongdurability,coaxialcableswereusedincomputer
networkingfornearlytwodecades(80sand90s).Coaxialcablesarenolonger
usedtobuildanytypeofcomputernetwork.
Specifications of coaxial cables
Coaxialcableshavebeeninuseforthelastfourdecades.Duringtheseyears,
basedonseveralfactorssuchasthethicknessofthesheath,themetalofthe
conductor,andthematerialusedininsulation,hundredsofspecificationshave
beencreatedtospecifythecharacteristicsofcoaxialcables.

15. Fromthesespecifications,onlyafewwereusedincomputernetworks.
Thefollowingtableliststhem.
TypeOhms AWG Conductor Description
RG-6 75
18
Solid copper Used in cable network to provide cable
Internet service and cable TV over long
distances.
RG-850
10
Solid copper Used in the earliest computer networks. This
cable was used as the backbone-cable in the
bus topology. In Ethernet standards, this cable
is documented as the 10base5
Thicknet cable.
RG-5850
24
Several thin strands of
copper
This cable is thinner, easier to handle and
install than the RG-8 cable. This cable was
used to connect a system with the backbone-
cable. In Ethernet standards, this cable is
documented as the 10base2 Thinnet cable.
RG-59 7520-22Solid copper Used in cable networks to provide short-
distance service.
-Coaxial cable uses RG rating to measure the materials used in shielding and conducting
cores.
-RG stands for the Radio Guide. Coaxial cable mainly uses radio frequencies in
transmission. Impedance is the resistance that controls the signals. It is expressed in the
ohms.
-AWG stands for American Wire Gauge. It is used to measure the size of the core. The
larger the AWG size, the smaller the diameter of the core wire.

16. b) Twisted-paircables
Usually,therearefourpairs.Eachpairhasonesolidcolorandonestripped
colorwire.Solidcolorsareblue,brown,greenandorange.Instrippedcolor,
thesolidcolorismixedwiththewhitecolor.Two types of twisted-pair cable
Basedonhowpairsarestrippedintheplasticsheath,therearetwotypesof
twisted-paircable;UTPandSTP.
1.IntheUTP(Unshieldedtwisted-pair)cable,allpairsarewrappedinasingle
plasticsheath.
2.IntheSTP(Shieldedtwisted-pair)cable,eachpairiswrappedwithan
additionalmetalshield,thenallpairsarewrappedinasingleouterplastic
sheath.

17. STP UTP
cantransmitdataat10Mbps,100Mbps,
1Gbps,and10Gbps.
cantransmitdataat10Mbps,100Mbps,
1Gbps,and10Gbps.
theSTPcablecontainsmorematerials,theUTPcablecontainslessmaterials,
itismoreexpensivethantheUTPcableitislessexpensivethantheSTPcable
BothcablesusethesameRJ-45(registered
jack)modularconnectors.
BothcablesusethesameRJ-45(registered
jack)modularconnectors
TheSTPprovidesmorenoiseandEMI
resistantthantheUTPcable.
TheUTPprovideslessnoiseandEMI
resistantthantheSTPcable.
Themaximumsegmentlengthforbothcables
is100metersor328feet.
Themaximumsegmentlengthforbothcables
is100metersor328feet.
Bothcablescanaccommodateamaximumof
1024nodesineachsegment.
Bothcablescanaccommodateamaximumof
1024nodesineachsegment.
SimilaritiesanddifferencesbetweenSTPandUTPcables

18. c) Fiber optic cable
Thiscableconsistsofcore,cladding,buffer,andjacket.Thecoreismadefrom
thethinstrandsofglassorplasticthatcancarrydataoverthelongdistance.The
coreiswrappedinthecladding;thecladdingiswrappedinthebuffer,andthe
bufferiswrappedinthejacket.Corecarriesthedatasignalsintheformofthe
light.Claddingreflectslightbacktothecore.
Bufferprotectsthelightfromleaking.Thejacketprotectsthecablefromphysical
damage.
FiberopticcableiscompletelyimmunetoEMIandRFI.Thiscablecantransmit
dataoveralongdistanceatthehighestspeed.Itcantransmitdataupto40
kilometersatthespeedof100Gbps.
Fiber optic uses light to send data. It reflects light from one endpoint to another.
Based on how many beams oflight are transmitted at a given time, there are two
types of fiber optical cable; SMF and MMF.

19. 1. SMF (Single-mode fiber) optical cable
•Thiscablecarriesonlyasinglebeamoflight.Thisismorereliableandsupports
muchhigherbandwidthandlongerdistancesthantheMMFcable.Thiscable
usesalaserasthelightsourceandtransmits1300or1550nano-meter
wavelengthsoflight.
2. MMF (multi-mode fiber) optical cable
•Thiscablecarriesmultiplebeamsoflight.Becauseofmultiplebeams,thiscable
carriesmuchmoredatathantheSMFcable.Thiscableisusedinshorter
distances.ThiscableusesanLEDasthelightsourceandtransmits850or1300
nano-meterwavelengthsoflight.
Twotypesoffiberopticalcable
FiberOpticCablingSolutions
Thelargestsolutionsofpre-terminatedfiberoptics,includingmultimodeand
single-modepatchcords, MTP/MPOfibertrunksandharnesses,plug-n-play
modules/cassettesandfiberenclosures.

20. DifferenceofStraightthroughandCrossoverCable
Ethernetcablescanbewiredasstraightthroughorcrossover.Thestraight
throughisthemostcommontypeandisusedtoconnectcomputerstohubsor
switches.Theyaremostlikelywhatyouwillfindwhenyougotoyourlocal
computerstoreandbuyapatchcable.CrossoverEthernetcableismore
commonlyusedtoconnectacomputertoacomputerandmaybealittle
hardertofindsincetheyaren’tusednearlyasmuchasstraightthrough
Ethernetcable.Then,what’sthedifferencebetweenstraightthroughvs
crossovercable?Readthroughthisposttofindtheanswer.
T568AAndT568BWiringStandardBasis
ARJ45connectorisamodular8position,8pinconnectorusedforterminating
Cat5epatchcableorCat6cable.Apinoutisaspecificarrangementofwires
thatdictatehowtheconnectoristerminated.Therearetwostandards
recognizedbyANSI,TIAandEIAforwiringEthernetcables.Thefirstisthe
T568AwiringstandardandthesecondisT568B.T568Bhassurpassed568A
andisseenasthedefaultwiringschemefortwistedpairstructuredcabling.If
youareunsureofwhichtouse,choose568B.
EXPERIMENT 1 PART 2

21. StraightThroughvsCrossoverCable

22. WhatIsStraightThroughCable?
Astraightthroughcableisatypeoftwistedpaircablethatisusedinlocalarea
networkstoconnectacomputertoanetworkhubsuchasarouter.Thistypeof
cableisalsosometimescalledapatchcableandisanalternativetowireless
connectionswhereoneormorecomputersaccessarouterthroughwireless
signal.
Onastraightthroughcable,thewiredpinsmatch.Straightthroughcableuse
onewiringstandard:bothendsuseT568Awiringstandardorbothendsuse
T568Bwiringstandard.Thefollowingfigureshowsastraightthroughcableof
whichbothendsarewiredastheT568Bstandard.
“Astraightthroughcableofwhichbothends”

23. WhatIsCrossoverCable?
AcrossoverEthernetcableisatypeofEthernetcableusedtoconnect
computingdevicestogetherdirectly.Unlikestraightthroughcable,theRJ45
crossovercableusestwodifferentwiringstandards:oneendusestheT568A
wiringstandardandtheotherendusestheT568Bwiringstandard.
TheinternalwiringofEthernetcrossovercablesreversesthetransmitand
receivesignals.Itismostoftenusedtoconnecttwodevicesofthesametype:
e.g.twocomputers(vianetworkinterfacecontroller)ortwoswitchestoeach
other.
“ACrossovercableofwhichbothends”

24. Straight through vs Crossover Cable, which to choose?
Straightthroughvscrossovercable,whichoneshouldIchoose?Usually,straight
throughcablesareprimarilyusedforconnectingunlikedevices.Andcrossover
cablesareuseforconnectingalikedevices.
Use straight through Ethernet cable for the following cabling:
Switch to router
Switch to PC or server Hub to
PC or server
Use crossover cables for the following cabling:
Switch to switch
Switch to hub
Hub to hub Router to router
Router Ethernet port to PC NIC
PC to PC

26. ConclusiononStraightThroughvsCrossoverCable
Straightthroughandcrossovercablesarewireddifferentlyfromeachother.
Oneeasywaytotellwhatyouhaveistolookattheorderofthecoloredwires
insidetheRJ45connector.Iftheorderofthewiresisthesameonbothends,
thenyouhaveastraightthroughcable.Ifnot,thenit’smostlikelyacrossover
cableorwaswiredwrong.
Atpresent,thestraightthroughcableismuchmorepopularthancrossovercable
andiswidelyusedbypeople.
FS.COMprovidesafullrangestraightthroughCat5e,Cat6,Cat6aandCat7
Ethernetcableswithmanylengthsandcolorsoptions.

27. NetworkcableCrimpingandTestingTools
InThispartofexperimentexplainsthemostcommontwisted-pairnetworkcable
testingandcrimpingtoolsindetail.Learnthetoolsthatyoucanusetocrimpand
testtwisted-pairnetworkcables.Cablesarethebackboneofawirednetwork.
Thestability,reliability,andperformanceofawirednetworkdependoncables.
Installingandmaintainingcablesinawirednetworkisadifficulttask.Tomake
thistaskeasier,avarietyofnetworkcablecrimpingandtestingtoolsare
available.Inthistutorial,wewillnotonlydiscusssomeofthemostcommon
networkcablecrimpingandtestingtoolsbutalsounderstandtheirfeaturesand
functions.
Twisted-pair(STPandUTP)networkcablecrimpingtools
Crimpingtoolsareusedforthefollowingpurposes.
1.Tocutthenetworkcableoftherequiredlengthfromthebundle.
2.Toremovetheouterandinnerjacketsofthenetworkcable.
3.Toattachtheconnectorsonbothendsofthecable.
EXPERIMENT 1 PART 3

28. Somecrimpingtoolsprovideallthefunctionalitywhileothersprovideone
ortwofunctionalities.
Themostcommontwisted-pairnetworkcablecrimpingtoolsare
describedbelow.
WireCutter:-Tocutthenetworkcableoftherequiredlengthfromthe
bundle,youcanuseanystandardwirecuttertoolorcanuseawirecutter
toolthatisspeciallydesignedforthetwisted-paircable.Atwisted-pair
wirecutterusuallyincludesadditionalbladesforstrippingthewire.
WireStripper:-Thistoolisusedtoremovetheouterandinnerjacketsof
thenetworkcable.Typically,youdonot
needtopurchasethistoolseparatelyasallstandardtwisted-pairwire
cuttersareequippedwithwire-strippers.
Crimptool:-Thistoolisusedtoattachtheconnectorstothecable.
Typically,thistoolalsoincludesawire-cutterandwire-stripper.Soifyou
buyacrimptool,youdon'thavetobuyawire-cutterandwire-striper
separately.

30. Basiccabletester
Thisdeviceprovidesallremainingfunctionalitiesofanetworkcablecertifier.It
cantestcablelength,crosstalk,andbreaksinthecable.Itcanalsocheck
whethertheconnectorsonbothendsofanetworkcableareproperlyattachedor
not.

31. Tonegeneratorandtheprobe
Thisdeviceisusedtotracetheunlabelednetworkcables.Thisdevicecomesin
twopieces:thetonegeneratorandtheprobe.Thetonegeneratorgeneratestones
orsignalsandplacesthemonthenetworkcable.Theprobedetectsthesesignals
ontheotherendofthecable.
Youcanusethistooltoidentifynetworkcablesthatrunfromacentrallocationto
remotelocations.Forexample,ifyouareworkingonapatch-panelorswitchand
tryingtofigureoutwhichnetworkcableconnectsbacktoanend-device(suchasa
PC),thenyoucanusethisdevice.Placeatonegeneratoratoneendofthe
connection(end-device),andusetheprobeonanotherside(switchorpatch-
panel)todeterminewhichnetworkcablethetonegeneratorisconnectedto.