搜索
PARTⅠ:ChoiceB1.Whichofthefollowingservicesdoesnotthetransportlayerprovidefortheapplicationlayer?A.In-orderdeliveryofdatasegmentsbetweenprocessesB.BesteffortdeliveryofdatasegmentsbetweencommunicatinghostsC.MultiplexinganddemultiplexingoftransportlayersegmentsD.CongestioncontrolA2.WhatarethetwoofthemostimportantprotocolsintheInternet?A.TCPandIPB.TCPandUDPC.TCPandSMTPD.ARPandDNSC3.TheInternetprovidestwoservicestoitsdistributedapplications:aconnectionorientedreliableserviceanda().A.connectionorientedunreliableserviceB.connectionlessreliableserviceC.connectionlessunreliableserviceD.InorderdatatransportserviceD4.Processesontwodifferentendsystemscommunicatewitheachotherbyexchanging()acrossthecomputernetwork.A.packetsB.datagramC.framesD.messagesA5.Thejobofdeliveringthedatainatransport-layersegmenttothecorrectsocketiscalled().A.demultiplexingB.multiplexingC.TDMD.FDMC6.TwoimportantreasonsthattheInternetisorganizedasahierarchyofnetworksforthepurposesofroutingare:A.LeastcostandmaximumfreecircuitavailabilityB.MessagecomplexityandspeedofconvergenceC.ScaleandadministrativeautonomyD.LinkcostchangesandlinkfailureB7.Whichofcharactersisnotdistance-vectoralgorithm’scharacters？（）A.iterativeB.globalC.asynchronousD.distributedD8.ThelengthofIPV6addressis（）bits.A.32B.48C.64D.128C9.ThehostcomponentofaCIDRaddressoftheforma.b.c.d/25cancontainaddressesfor:A.225hosts(minus“special”hosts)B.512hosts(minus“special”hosts)C.2(32-25)hosts(minus“special”hosts)D.25hosts(minus“special”hosts)C10.Theprimaryfunctionoftheaddressresolutionprotocol(ARP)thatresidesinInternethostsandroutersis:A.ToprovideLANrouterfunctionsB.TotranslatebetweenLANaddressesandphysicalinterfaceaddressesC.TotranslateIPaddressestoLANaddressesD.TocalculatetheshortestpathbetweentwonodesonaLANA11.ThePOP3protocolrunsover____andusesport____.A.TCP110B.UDP110C.UDP25D.TCP25D12.Whenadestinationhosttransportlayerreceivesdatafromthenetworklayer,itunambiguouslyidentifiestheappropriateprocesstopassthedatatobyusingatripletconsistingof:A.Sourceport#,destinationIPaddress,andsourceIPaddressB.Destinationport#,sourceport#,processID#C.Destinationport#,sourceport#,destinationIPaddressD.Destinationport#,sourceport#,sourceIPaddressD13.Fromthelistbelow,selecttheitemsfoundintheTCPsegmentstructurethatarenotfoundintheUDPsegmentstructure:A.ApplicationGeneratedDataB.DestinationPort#C.SourcePort#D.Sequence#A14.TheRIProutingprotocolisbasedonanalgorithmthatis:A.Basedoninformationreceivedonlyfromlink“neighbors”B.AlinkstatealgorithmC.AnOSPFalgorithmD.AcentralizedroutingalgorithmB15.Withanexteriorroutingprotocol,whichofthefollowingissuesgenerallydominatestheroutingdecisions?A.GeographicaldistancebetweenAS’sB.PolicyC.NumberofAS’straversedD.CurrentcongestionlevelsintheAS’sA1.Endsystemareconnectedtogetherby____.A.communicationlinksB.applicationlayerC.transportlayerD.thenetworklayerC2.Whichapplication’sNOTusingTCP?A.SMTPB.HTTPC.DNSD.AllofthemB3.Inthepollingprotocols,themasternodepollseachofthenodesina/an____fashion.A.randomB.appointedC.round-robinD.uncirculatedC4.TheDNSprotocolrunsover____andusesport____.A.UDP36B.TCP36C.UDP53D.TCP53A5.TCPprovidesa____servicetoitsapplicationstoeliminatethepossibilityofthesenderover-flowingthereceiver’sbuffer.A.flow-controlB.congestioncontrolC.reliabilitycontrolD.dataconnectionD6.Wecanclassifyjustaboutanymultipleaccessprotocolasbelongingtooneofthreecategories:channelpartitioningprotocols,randomaccessprotocols,and____.A.addressresolutionprotocolsB.DynamichostconfigurationprotocolsC.link-controlprotocolsD.taking-turnsprotocolsB8.Themaximumtransferunit(MTU)inEthernetframestructureis()byte.A.1000B.1500C.800D.2000B9.ThesocketofUDPisidentifiedby_____and_______.A.sourceIPaddressandsourceportnumberB.destinationIPaddressanddestinationportnumber.C.sourceIPaddressanddestinationportnumber.D.destinationIPaddressandsourceIPaddress.C10.Whichisnotplugandplayinthefollowingfouritems?A.DHCPB.HubsC.RoutersD.SwitchesD11．Whichofroutersisnotdefaultrouters?A.first-hoprouterB.sourcerouterC.destinationrouterD.second-hoprouterB13.ICMPis_____.A.theprotocolofApplicationlayerB.theprotocolofnetworklayerC.theprotocoloftransportlayerD.notapartofTCP/IPprotocolsB14.Asgeneral,wehasfollowingchannelpartitioningprotocolsexcept____.A.TDMB.CSMAC.FDMD.CDMAD15.____ismostusedforerrorreporting.A.UDPB.SMTPC.FTPD.ICMPB16.TheheaderofIPV6is____byte.A.20B.40C.60D.80B17.Inthenetworklayertheseservicearehost-to-hostserviceprovidedby____.（B）A.thetransportlayertothenetworklayerB.thenetworklayertothetransportlayerC.thenetworklayertothenetworklayerD.thetransportlayertothetransportlayerA18.Ifthereisnotenoughmemorytobufferanincomingpacket,apolicythatdropthearrivingpacketcalled____.A.drop-tailB.packetlossC.protocolD.encapsulationC19.Ineithercase,a____receivesroutingprotocolmessages,whichareusedtoconfigureitsforwardingtable.A.serverB.hostC.routerD.ModemD20.WhichofthefollowingfunctionsdoesnotbelongtoPPP___.A.framingB.link-controlprotocolsC.network-controlprotocolsD.errorcorrectionB1.WhichofthefollowingservicesdoestheInternetnetworklayerprovidef