計算機網(wǎng)絡(luò)英文題庫

1、精選優(yōu)質(zhì)文檔-傾情為你奉上Chapter1ComputerNetworksandtheInternet1The()isaworldwidecomputernetwork,thatis,anetworkthatinterconnectsmillionsofcomputingdevicesthroughouttheworld.ppt3ApublicInternetBIntranetCswitchnetDtelevisionnet2Whichkindofmediaisnotaguidedmedia?()Atwisted-paircopperwireBacoaxialcableCfiberoptics

2、Ddigitalsatellitechannel3Whichkindofmediaisaguidedmedia?()AgeostationarysatelliteBlow-altitudesatelliteCfiberopticsDwirelessLAN4Theunitsofdataexchangedbyalink-layerprotocolarecalled().AFramesBSegmentsCDatagramsDbitstreams5Whichofthefollowingoptionbelongstothecircuit-switchednetworks?()AFDMBTDMCVCnet

3、worksDbothAandB6()makessurethatneithersideofaconnectionoverwhelmstheothersidebysendingtoomanypacketstoofast.AReliabledatatransferBFlowcontrolCCongestioncontrolDHandshakingprocedure7()meansthattheswitchmustreceivetheentirepacketbeforeitcanbegintotransmitthefirstbitofthepacketontotheoutboundlink.AStor

4、e-and-forwardtransmissionBFDMCEnd-to-endconnectionDTDM8Datagramnetworksandvirtual-circuitnetworksdifferinthat().Adatagramnetworksarecircuit-switchednetworks,andvirtual-circuitnetworksarepacket-switchednetworks.Bdatagramnetworksarepacket-switchednetworks,andvirtual-circuitnetworksarecircuit-switchedn

5、etworks.Cdatagramnetworksusedestinationaddressesandvirtual-circuitnetworksuseVC.numberstoforwardpacketstowardtheirdestination.DdatagramnetworksuseVC.numbersandvirtual-circuitnetworksusedestinationaddressestoforwardpacketstowardtheirdestination.9Inthefollowingoptions,whichoneisnotaguidedmedia?()Atwis

6、ted-pairwireBfiberopticsCcoaxialcableDsatellite10Processingdelaydoesnotincludethetimeto().AexaminethepacketsheaderBwaittotransmitthepacketontothelinkCdeterminewheretodirectthepacketDcheckbit-errorinthepacket11Inthefollowingfourdescriptions,whichoneiscorrect?()AThetrafficintensitymustbegreaterthan1.B

7、Thefractionoflostpacketsincreasesasthetrafficintensitydecreases.CIfthetrafficintensityisclosetozero,theaveragequeuingdelaywillbeclosetozero.DIfthetrafficintensityisclosetoone,theaveragequeuingdelaywillbeclosetoone.12TheInternetsnetworklayerisresponsibleformovingnetwork-layerpacketsknownas()fromoneho

8、sttoanother.AframeBdatagramCsegmentDmessage13Theprotocolsofvariouslayersarecalled().AtheprotocolstackBTCP/IPCISPDnetworkprotocol14Therearetwoclassesofpacket-switchednetworks:()networksandvirtual-circuitnetworks.AdatagramBcircuit-switchedCtelevisionDtelephone15Accessnetworkscanbelooselyclassifiedinto

9、threecategories:residentialaccess,companyaccessand()access.AcabledBwirelessCcampusDcityareaQuestion1617Suppose,aistheaveragerateatwhichpacketsarriveatthequeue,Risthetransmissionrate,andallpacketsconsistofLbits,thenthetrafficintensityis(16),anditshouldnogreaterthan(17).16 ALRaBLaRCRaLDLRa17A2B1C0D-11

10、8IntheInternet,theequivalentconcepttoendsystemsis().AhostsBserversCclientsDrouters19IntheInternet,endsystemsareconnectedtogetherby().AcopperwireBcoaxialcableCcommunicationlinksDfiberoptics20EndsystemsaccesstotheInternetthroughits().AmodemsBprotocolsCISPDsockets21Endsystems,packetswitches,andotherpie

11、cesoftheInternet,run()thatcontrolthesendingandreceivingofinformationwithintheInternet.AprogramsBprocessesCapplicationsDprotocols22Therearemanyprivatenetworks,suchasmanycorporateandgovernmentnetworks,whosehostscannotexchangemessageswithhostsoutsideoftheprivatenetwork.Theseprivatenetworksareoftenrefer

12、redtoas().AinternetsBLANCintranetsDWAN23Theinternetallows()runningonitsendsystemstoexchangedatawitheachother.AclientsapplicationsBserverapplicationsCP2PapplicationsDdistributedapplications24TheInternetprovidestwoservicestoitsdistributedapplications:aconnectionlessunreliableserviceand()service.Aflowc

13、ontrolBconnection-orientedreliableCcongestioncontrolDTCP25Itdefinestheformatandtheorderofmessagesexchangedbetweentwoormorecommunicatingentities,aswellastheactionstakenonthetransmissionand/orreceiptofamessageorotherevent.Thesentencedescribes().AInternetBprotocolCintranetDnetwork26Inthefollowingoption

14、s,whichdoesnotdefineinprotocol?()AtheformatofmessagesexchangedbetweentwoormorecommunicatingentitiesBtheorderofmessagesexchangedbetweentwoormorecommunicatingentitiesCtheactionstakenonthetransmissionofamessageorothereventDthetransmissionsignalsaredigitalsignalsoranalogsignals27Inthefollowingoptions,wh

15、ichisdefinedinprotocol?()Atheactionstakenonthetransmissionand/orreceiptofamessageorothereventBtheobjectsexchangedbetweencommunicatingentitiesCthecontentintheexchangedmessagesDthelocationofthehosts28Inthefollowingoptions,whichdoesnotbelongtothenetworkedge?()AendsystemsBroutersCclientsDservers29Inthef

16、ollowingoptions,whichbelongstothenetworkcore?()AendsystemsBroutersCclientsDservers30Inthefollowingoptions,whichisnotthebundledwiththeInternetsconnection-orientedservice?()AreliabledatatransferBguaranteeofthetransmissiontimeCflowcontrolDcongestion-control31Anapplicationcanrelyontheconnectiontodeliver

17、allofitsdatawithouterrorandintheproperorder.Thesentencedescribes().AflowcontrolBcongestion-controlCreliabledatatransferDconnection-orientedservice32Itmakessurethatneithersideofaconnectionoverwhelmstheothersidebysendingtoomanypacketstoofast.Thesentencedescribes().AflowcontrolBcongestion-controlCconne

18、ction-orientedserviceDreliabledatatransfer33IthelpspreventtheInternetfromenteringastateofgridlock.Whenapacketswitchbecomescongested,itsbufferscanoverflowandpacketlosscanoccur.Thesentencedescribes().AflowcontrolBcongestion-controlCconnection-orientedserviceDreliabledatatransfer34TheInternetsconnectio

19、n-orientedservicehasaname,itis().ATCPBUDPCTCP/IPDIP35Inthefollowingoptions,whichservicedoesnotbeprovidedtoanapplicationbyTCP?()AreliabletransportBflowcontrolCvideoconferencingDcongestioncontrol36TheInternetsconnectionlessserviceiscalled().ATCPBUDPCTCP/IPDIP37Inthefollowingoptions,whichdoesnotuseTCP?

20、()ASMTPBinternettelephoneCFTPDHTTP38Inthefollowingoptions,whichdoesnotuseUDP?()AInternetphoneBvideoconferencingCstreamingmultimediaDtelnet39Therearetwofundamentalapproachestobuildinganetworkcore,()andpacketswitching.AelectricalcurrentswitchingBcircuitswitchingCdataswitchingDmessageswitching40In()net

21、works,theresourcesneededalongapathtoprovideforcommunicationbetweentheendsystemarereservedforthedurationofthecommunicationsession.Apacket-switchedBdata-switchedCcircuit-switchedDmessage-switched41In()networks,theresourcesarenotreserved;asessionsmessagesusetheresourcesondemand,andasaconsequence,mayhav

22、etowaitforaccesstocommunicationlink.Apacket-switchedBdata-switchedCcircuit-switchedDmessage-switched42Inacircuit-switchednetwork,ifeachlinkhasncircuits,foreachlinkusedbytheend-to-endconnection,theconnectiongets()ofthelinksbandwidthforthedurationoftheconnection.Aafraction1/nBallC1/2Dntimes43For(),the

23、transmissionrateofacircuitisequaltotheframeratemultipliedbythenumberofbitsinaslot.ACDMABpacket-switchednetworkCTDMDFDM44()meansthattheswitchmustreceivetheentirepacketbeforeitcanbegintotransmitthefirstbitofthepacketontotheoutboundlink.AQueuingdelayBStore-and-forwardtransmissionCPacketlossDPropagation

24、45Thenetworkthatforwardspacketsaccordingtohostdestinationaddressesiscalled()network.Acircuit-switchedBpacket-switchedCvirtual-circuitDdatagram46Thenetworkthatforwardspacketsaccordingtovirtual-circuitnumbersiscalled()network.Acircuit-switchedBpacket-switchedCvirtual-circuitDdatagram47Inthefollowingen

25、tries,whichisnotakindofaccessnetwork?()AresidentialaccessBcompanyaccessCwirelessaccessDlocalaccess48Supposethereisexactlyonepacketswitchbetweenasendinghostandareceivinghost.ThetransmissionratesbetweenthesendinghostandtheswitchandbetweentheswitchandthereceivinghostareR1andR2,respectively.Assumingthat

26、theswitchusesstore-and-forwardpacketswitching,whatisthetotalend-to-enddelaytosendapacketoflengthL?(Ignorequeuingdelay,propagationdelay,andprocessingdelay.)()AL/R1L/R2BL/R1CL/R2Dnoneoftheabove49Thetimerequiredtoexaminethepacketsheaderanddeterminewheretodirectthepacketispartofthe().AqueuingdelayBprocessingdelayCpropagationdelayDtransmissiondelay50Thetimerequiredtopropagatefromthebeginningofthelinktothenextrouteris().AqueuingdelayBprocessingdelayCpropag