計算機網(wǎng)絡(luò)英文題庫(附答案)chapter5

Chapter5TheLinkLayerandLocalAreaNetwork1．A()protocolisusedtomoveadatagramoveranindividuallink.Aapplication-layerBtransport-layerCnetwork-layerDlink-layer2．Theunitsofdataexchangedbyalink-layerprotocolarecalled().AdatagramsBframesCsegmentsDmessages3．Whichofthefollowingprotocolsisnotalink-layerprotocol?()AEthernetBPPPCHDLCDIP4．Inthefollowingfourdescriptions,whichoneisnotcorrect?()Alink-layerprotocolhasthenode-to-nodejobofmovingnetwork-layerdatagramsoverasinglelinkinthepath.BTheservicesprovidedbythelink-layerprotocolsmaybedifferent.CAdatagrammustbehandledbythesamelink-layerprotocolsonthedifferentlinksinthepath.DTheactionstakenbyalink-layerprotocolwhensendingandreceivingframesincludeerrordetection,flowcontrolandrandomaccess.5．Whichofthefollowingservicescannotofferedbyalink-layerprotocol?()AcongestioncontrolBLinkAccessCErrorcontrolDFraming6．()protocolservestocoordinatetheframetransmissionsofthemanynodeswhenmultiplenodesshareasinglebroadcastlink.AARPBMACCICMPDDNS7．Inthefollowingfourdescriptionsabouttheadapter,whichoneisnotcorrect?()ATheadapterisalsocalledasNIC.BTheadapterisasemi-autonomousunit.CThemaincomponentsofanadapterarebusinterfaceandthelinkinterface.DTheadaptercanprovideallthelink-layerservices.8．ConsiderCRCerrorcheckingapproach,thefourbitgeneratorGis1011,andsupposethatthedataDis10101010,thenthevalueofRis().ABCD0101000111109．Inthefollowingfourdescriptionsaboutrandomaccessprotocol,whichoneisnotcorrect?()AInslottedALOHA,nodescantransmitatrandomtime.BInpureALOHA,ifaframeexperiencesacollision,thenodewillimmediatelyretransmititwithprobabilityp.CDThemaximumefficiencyofaslottedALOHAishigherthanapureALOHA.InCSMA/CD,onenodelistenstothechannelbeforetransmitting.10．InthefollowingdescriptionsaboutMACaddress,whichoneisnotcorrect?()ABCDTheMACaddressistheaddressofonenode’sadapter.NotwoadaptershavethesameMACaddress.TheMACaddressdoesn’tchangenomatterwheretheadaptergoes.MACaddresshasahierarchicalstructure.11．TheARPprotocolcantranslate()into().()ABChostname,IPaddresshostname,MACaddressIPaddress,MACaddressDbroadcastaddress,IPaddress12．ThevalueofPreamblefieldinEthernetframestructureis()A1010101010101010……1010101011111111B1010101110101011……1010101110101011C1010101010101010……1010101010101011D1010101010101010……101010101010101013．TherearefourstepsinDHCP,theDHCPservercancomplete().ADHCPserverdiscoveryBDHCPserveroffersCDHCPrequestDDHCPresponse14．InCSMA/CD,theadapterwaitssometimeandthenreturnstosensingthechannel.Inthefollowingfourtimes,whichoneisimpossible?()A0bittimesB512bittimesC1024bittimesD1028bittimes15．ThemostcommonEthernettechnologiesare10BaseTand100BaseT.“10”and“100”indicate().AthemaximumlengthbetweentwoadaptersBtheminimumlengthbetweentwoadaptersCthetransmissionrateofthechannelDthetransmissionrateofthenode16．TheprincipalcomponentsofPPPincludebutnot().AframingBphysical-controlprotocolClink-layerprotocolDnetwork-layerprotocol17．Inthefollowingfouroptions,whichservicecannotbeprovidedbyswitch?()AfilteringBself-learningCforwardingDoptimalrouting18．Inthefollowingfourservices,whichonewasberequiredinPPP?()ApacketframingBerrordetectionCerrorcorrectionDmultipletypesoflink19．Theabilitytodeterminetheinterfacestowhichaframeshouldbedirected,andthendirectingtheframetothoseinterfacesis().AfilteringBforwardingCself-learningDoptimalrouting20．In()transmission(s),thenodesatbothendsofalinkmaytransmitpacketsatthesametime.Afull-duplexBhalf-duplexCsingle-duplexDbothfull-duplexandhalf-duplex21．ConsiderthedataDis01110010001,ifuseevenparitycheckingapproach,theparitybitis(①),ifuseoddparitycheckingapproach,theparitybitis(②).()A①0②1B①0②0C①1②1D①1②022．Inthefollowingfourdescriptionsaboutparitychecks,whichoneiscorrect?()ASingle-bitparitycandetectallerrors.BSingle-bitparitycancorrectoneerrors.CTwo-dimensionalparitynotonlycandetectasinglebiterror,butalsocancorrectthaterror.DTwo-dimensionalparitynotonlycandetectanycombinationoftwoerrors,butalsocancorrectthem.23．MACaddressis()bitslong.A32B48C128D6424．WirelessLANusingprotocol().AIEEE802.3BIEEE802.4CIEEE802.5DIEEE802.1125．Thefollowingprotocolsarebelongingtomultipleaccessprotocolsexceptfor().AchannelpartitioningprotocolsBroutingprotocolsCrandomaccessprotocolsDtaking-turnsprotocols26．Whichofthefollowingisnotbelongingtochannelpartitioningprotocols?()ACSMABFDMCCDMADTDM27．InthefollowingfourdescriptionsaboutCSMA/CD,whichoneisnotcorrect?()AAnodelistenstothechannelbeforetransmitting.BIfsomeoneelsebeginstalkingatthesametime,stoptalking.CAtransmittingnodelistenstothechannelwhileitistransmitting.DWithCSMA/CD,thecollisionscanbeavoidedcompletely.28．()providesamechanismfornodestotranslateIPaddressestolink-layeraddress.AIPBARPCRARPDDNS29．AMACaddressisa()address.Aphysical-layerBapplication-layerClink-layerDnetwork-layer30．Whichofthefollowingiscorrect?()ANotwoadaptershavethesameMACaddress.BMACbroadcastaddressisFF-FF-FF-FF-FF-FF.CAportablecomputerwithanEthernetcardalwayshasthesameMACaddress,nomatterwherethecomputergoes.DAlloftheabove31．Inthefollowingfourdescriptions,whichoneisnotcorrect?()AARPresolvesanIPaddresstoaMACaddress.BDNSresolveshostnamestoIPaddresses.CDNSresolveshostnamesforhostsanywhereintheInternet.DARPresolvesIPaddressesfornodesanywhereintheInternet.32．IntheLAN,()protocoldynamicallyassignIPaddressestohosts.ADNSBARPCDHCPDIP33．DHCPprotocolisafour-stepprocess:①DHCPrequest.②DHCPACK.③DHCPserverdiscovery.④DHCPserveroffer(s).Thecorrectsequenceis()A①②③④B③②①④C③④①②D①④③②34．IntheEthernetframestructure,theCRCfieldis()bytes.A2B4C8D3235．IntheEthernetframestructure,theDatafieldcarriesthe().AIPdatagramBsegmentCframeDmessage36．Inthefollowingfourdescriptions,whichoneisnotcorrect?()AEthernetusesbasebandtransmission.BAlloftheEthernettechnologiesprovideconnection-orientedreliableservicetothenetworklayer.CTheEthernet10Base2technologyusesathincoaxialcableforthebus.DTheEthernet10BaseTtechnologyusesastartopology.37．Ethernet’smultipleaccessprotocolis().ACDMABCSMA/CDCslottedALOHADtoken-passingprotocol38．InthefollowingfourdescriptionsaboutCSMA/CD,whichoneisnotcorrect?()AAnadaptermaybegintotransmitatanytime.BAnadapternevertransmitsaframewhenitsensesthatsomeotheradapteristransmitting.CAtransmittingadapterabortsitstransmissionassoonasitdetectsthatanotheradapterisalsotransmitting.DAnadapterretransmitswhenitdetectsacollision.39．WhichofthefollowingdescriptionsaboutCSMA/CDiscorrect?()ANoslotsareused.BItusescarriersensing.CItusescollisiondetection.DAlloftheabove.40．TheEthernet10BaseTtechnologyuses()asitsphysicalmedia.AfiberopticsBtwisted-paircopperwireCcoaxialcableDsatelliteradiochannel41．For10BaseT,themaximumlengthoftheconnectionbetweenanadapterandthehubis()meters.A100B200C500D1042．A()isaphysical-layerdevicethatactsonindividualbitsratherthanonframes.AswitchBhubCrouterDgateway43．Ahubisa()devicethatactsonindividualbitsratherthanonframes.Aphysical-layerBlink-layerCnetwork-layerDransport-layer44．Aswitchisa()devicethatactsonframe.Aphysical-layerBlink-layerCnetwork-layerDtransport-layer45．Inthefollowingfourdescriptions,whichoneisnotcorrect?()ASwitchescaninterconnectdifferentLANtechnologies.BHubscaninterconnectdifferentLANtechnologies.CThereisnolimittohowlargeaLANcanbewhenswitchesareusedtointerconnectLANsegments.DThereisrestrictiononthemaximumallowablenumberofnodesinacollisiondomainwhenhubsareusedtointerconnectLANsegments.46．Theabilitytodeterminewhetheraframeshouldbeforwardedtosomeinterfaceorshouldjustbedroppedis().ABCfilteringforwardingself-learningDoptimalrouting47．Whichofthefollowingdevicesisnotaplugandplaydevice?()AhubBrouterCswitchDrepeater48．Whichofthefollowingdevicesisnotcut-throughdevice?()AhubBrouterCswitchDrepeater49．Inthefollowingfourdescriptions,whichoneisnotcorrect?()ASwitchesdonotofferanyprotectionagainstbroadcaststorms.BRoutersprovidefirewallprotectionagainstlayer-2broadcaststorms.CBothswitchesandroutersareplugandplaydevices.DArouterisalayer-3packetswitch,aswitchisalayer-2packetswitch.50．Whichdevicehasthesamecollisiondomain?()AHubBSwitchCRouterDBridge51．IEEE802.2protocolbelongto()layerAnetworkBMACCLLCDphysical52．IEEE802.11protocoldefines()rules.AEthernetBusBwirelessWANCwirelessLANDTokenBus53．Indatalink-layer,whichprotocolisusedtosharebandwidth?()ASMTPBICMPCARPDCSMA/CD54．WhentwoormorenodesontheLANsegmentstransmitatthesametime,therewillbeacollisionandallofthetransmittingnodeswellenterexponentialback-off,thatisalloftheLANsegmentsbelongtothesame().AcollisiondomainBswitchCbridgeDhub55．()allowsdifferentnodestotransmitsimultaneouslyandyethavetheirrespectivereceiverscorrectlyreceiveasender’sencodeddatabits.ACDMABCSMACCSMA/CDDCSMA/CA56．Becausetherearebothnetwork-layeraddresses(forexample,InternetIPaddresses)andlink-layeraddresses(thatis,LANaddresses),thereisaneedtotranslatebetweenthem.FortheInternet,thisisthejobof().ARIPBOSPFCARPDIP57．PPPdefinesaspecialcontrolescapebyte,().Iftheflagsequence,01111110appearsanywhereintheframe,exceptintheflagfield,PPPprecedesthatinstanceoftheflagpatternwiththecontrolescapebyte.A01111110B01111101C10011001D1011111058．Thedevice()canisolatecollisiondomainsforeachoftheLANsegment.AmodemBswitchChubDNIC59．InthefollowingfourdescriptionsaboutPPP,whichoneisnotcorrect?()APPPisrequiredtodetectandcorrecterrors.BPPPisnotrequiredtodeliverframestothelinkreceiverinthesameorderinwhichtheyweresentbythelinksender.CPPPneedonlyoperateoverlinksthathaveasinglesenderandasinglereceiver.DPPPisnotrequiredtoprovideflowcontrol.60．InthePPPdataframe,the()fieldtellsthePPPreceiverstheupper-layerprotocoltowhichthereceivedencapsulateddatabelongs.AflagBcontrolCprotocolDchecksum61．PPP’slink-controlprotocols(LCP)accomplish().AinitializingthePPPlinkBmaintainingthePPPlinkCtakingdownthePPPlinkDalloftheabove62．ThePPPlinkalwaysbeginsinthe()stateandendsinthe()state.()Aopen,terminatingBopen,deadCdead,deadDdead,terminating63．For()linksthathaveasinglesenderatoneendofthelinkandasinglereceiverattheotherendofthelink.Apoint-to-pointBbroadcastCmulticastDalloftheabove64．With()transmission,thenodesatbothendsofalinkmaytransmitpacketsatthesametime.Ahalf-duplexBfull-duplexCsimplex(單工)Dsynchronous65．With()transmission,anodecannotbothtransmitandreceiveatthesametime.Ahalf-duplexBfull-duplexCsimplex(單工)Dsynchronous66．Whichofthefollowingfunctionscan’tbeimplementedintheNIC?()AencapsulationanddecapsulationBerrordetectionCmultipleaccessprotocolDrouting67．Whichofthefollowingfourdescriptionsiswrong?()AThebusinterfaceofanadapterisresponsibleforcommunicationwiththeadapter’sparentnode.BThelinkinterfaceofanadapterisresponsibleforimplementingthelink-layerprotocol.CThebusinterfacemayprovideerrordetection,randomaccessfunctions.DThemaincomponentsofanadapterarethebusinterfaceandthelinkinterface.68．Foroddparityschemes,whichofthefollowingiscorrect?()A011010001B111000110C110101110D00011011069．()dividestimeintotimeframesandfurtherdivideseachtimeframeintoNtimeslots.AFDMBTMDCCDMADCSMA70．WithCDMA,eachnodeisassignedadifferent()AcodeBtimeslotCfrequencyDlink71．Whichofthefollowingfourdescriptionsaboutrandomaccessprotocolisnotcorrect?()AAtransmissionnodetransmitsatthefullrateofthechannelBWhenacollisionhappens,eachnodeinvolvedinthecollisionretransmitsatonce.CBothslottedALOHAandCSMA/CDarerandomaccessprotocols.DWithrandomaccessprotocol,theremaybeemptyslots.72．PPPdefinesaspecialcontrolescapebyte01111101.Ifthedataisb1b201111110b3b4b5,thevalueis()afterbytestuffing.Ab1b20111110101111110b3b4b5Bb1b20111111001111101b3b4b5Cb5b4b30111111001111101b2b1Db5b4b30111110101111110b2b173．MACaddressisin()ofthecomputer.ARAMBNICCharddiskDcache74．Whichofthefollowingiswrong?()AARPtableisconfiguredbyasystemadministratorBARPtableisbuiltautomaticallyCARPtableisdynamicDARPtablemapsIPaddressestoMACaddresses75．NICworksin()layer.AphysicalBlinkCnetworkDtransport76．InLAN,ifUTPisused,thecommonconnectoris().AAUIBBNCCRJ-45DNNI77．Themodem’sfunction(s)is(are)().AtranslatesdigitalsignalintoanalogsignalBtranslatesanalogsignalintodigitalsignalCbothtranslatesanalogsignalintodigitalsignalandtranslatesdigitalsignalintoanalogsignalDtranslatesonekindofdigitalsignalintoanotherdigitalsignal78．()definesToken-Ringprotocol.AIEEE802.3BIEEE802.4CIEEE802.5DIEEE802.279．()definesToken-Busprotocol.AIEEE802.3BIEEE802.4CIEEE802.5DIEEE802.280．()definesCSMA/CDprotocol.AIEEE802.3BIEEE802.4CIEEE802.5DIEEE802.281．Thecomput