计算机网络英文题库(附答案)chapter2

1Chapter2ApplicationLayer1.Inthefollowingfourdescriptions,whichoneiscorrect?AInC/Sarchitecture,clientscommunicatewitheachotherdirectly.BInC/Sarchitecture,clienthasafixedwell-knownaddress.CInP2Parchitecture,peerscommunicatewitheachotherdirectly.DInP2Parchitecture,peerhasafixedwell-knownaddress.2.Inthecontextofacommunicationsessionbetweenapairofprocess,theprocessthatinitiatesthecommunicationislabeledasthe,theprocessthatwaitstobecontactedtobeginthesessionislabeledasthe.Aclientprocess,serverprocessBsendingprocess,receivingprocessCinputprocess,outputprocessDcommunicatingprocess,connectingprocess3.Asocketistheinterfacebetweenwithinahost.AthenetworklayerandthelinklayerBthelinklayerandthephysicallayerCtheapplicationlayerandthetransportlayerDthetransportlayerandthenetworklayer4.Inthefollowingapplications,whichoneisaloss-tolerantapplication?AE-mailBfiletransferCinstantmessagingDreal-timeaudio5.Inthefollowingapplications,whichoneisabandwidth-sensitiveapplication?AE-mailBwebapplicationCreal-timeaudioDfiletransfer6.TheserviceofTCPcan’tguarantee.AdeliveryofalldatawithouterrorBdeliveryofalldataintheproperorderCtherateofdeliveryDcongestioncontrol7.Inthefollowingapplications,whichoneusesUDP?2AE-mailBwebapplicationCfiletransferDDNS8.InthefollowingdescriptionsaboutHTTP,whichoneisnotcorrect?AHTTPusesnon-persistentconnectionsinitsdefaultmode.BHTTPusesTCPasitsunderlyingtransportprotocol.CHTTPisastatelessprotocol.DHTTPisclient-serverarchitecture.9.SupposeawebpageconsistsofabaseHTMLfile,5JEPGimagesandajavaapplet,andalsosupposeHTTPusespersistentconnectionwithoutpipelining,thetotalresponsetimeis.A2RTTB8RTTC12RTTD14RTT10.InHTTPresponsemessage,iftherequestedHTTPprotocolversionisnotsupported,thestatuscodeis.A200B301C400D5051~5CACDC6~10CDABD11.Theportnumberofwebapplicationis.A25B20C80D5312.AnetworkentitythatsatisfiesHTTPrequestsonthebehalfofanoriginwebserveris.AserverfarmBserverstackCproxyserverDedgeserver13.Inthefollowingdescriptionsaboutpersistentconnection,whichoneisnotcorrect?ATheserverleavestheTCPconnectionopenaftersendingaresponse.BEachTCPconnectionisclosedaftertheserversendingoneobject.CTherearetwoversionsofpersistentconnection:withoutpipeliningandwithpipelining.3DThedefaultmodeofHTTPusespersistentconnectionwithpipelining.14.FTPusestwoparallelTCPconnectionstotransferafile,thereare.AcontrolconnectionanddataconnectionBreceivingconnectionandsendingconnectionCclientconnectionandseverconnectionDprogramconnectionandprocessconnection15.InthefollowingdescriptionsaboutFTP,whichoneiscorrect?AFTPisp2parchitecture.BFTPsendsitscontrolinformationout-of-band.CFTPusespersistentconnection.DFTPisastatelessprotocol.16.InthecommandsofFTP,whichonedoesnothaveparameter?AUSERBPASSCLISTDSTOR17.TheInternetmailsystemhasthreecomponentswhichtheyare.Auseragent,SMTP,POP3BSMTP,POP3,IMAPCuseragent,SMTP,IMAPDuseragent,SMTP,mailserver18.IfthestatuscodeinHTTPresponsemessageis404,itmeans.ARequestsucceeded.BTherequesteddocumentdoesn’texitonthisserver.CThisisagenericerrorcodeindicatingthattherequestcouldnotbeunderstoodbytheserver.DRequestedobjecthasbeenpermanentlymover.19.ComparisonHTTPwithSMTP,thecorrectis.AHTTPisapushprotocol,andSMTPisapullprotocol.BInthedefaultmode,bothofthemusepersistentconnection.CHTTPplacesallofthemessage’sobjectsintoonemessage,andSMTPsendseveryobject4onebyone.DHTTPrequireseachmessagetobein7-bitASCIIformat,andSMTPdoesn’timposethisrestriction.20.TheheadersintheMIMEmessagemustincludeexcept.AFromBContent-typeCContent-transfer-encodingDMIMEversion11~15CCBAB16~20DDBBD21.Inthefollowingprotocol,whichoneisstateless?APOP3BSMTPCFTPDIMAP22.DNSmeans.ADataNameSystemBDataNationalSystemCDomainNameSystemDDomainNationalSystem23.TherearethreeclassesofDNSserverexcept.ARootDNSserverBLocalDNSserverCTLDserverDAuthoritativeDNSserver24.DNSprovidessomeservicesexcept.AHostaliasingBMailserveraliasingCLoaddistributionDAsinglepointoffailure25.TherearethreearchitecturesforlocatingcontentinP2Pfilesharing,KaZaAuses.ACentralizedDirectory（Napster）BQueryFlooding(Gnutella)CExploitingHeterogeneity(p141)DIncentivePriorities526.TherearethreearchitecturesforlocatingcontentinP2Pfilesharing,Napsteruses.ACentralizedDirectory(p137)BQueryFloodingCExploitingHeterogeneityDIncentivePriorities27.ThefollowingarchitecturesinP2Pfilesharing,whichisanoverlaynetwork?ACentralizedDirectoryBQueryFlooding(p139)CExploitingHeterogeneityDIncentivePriorities28.Thetimeittakesforasmallpackettotravelfromclienttoserverandthenbacktotheclientis.Around-traveltimeBnext-hoptimeCround-triptimeDprefix-matchingtime29.SupposeA(withaWeb-basede-mailaccount)sendsamessagetoB(whoaccesseshismailserverusingPOP3),whichapplication-layerprotocolisnotused?AHTTPBSMTPCPOP3DIMAP30.Inthefourfollowingoptions,whichprotocolisincludedinMailAccessProtocol?ASMTPBDHCPCIMAPDFTP31.InFTPcommands,isusedtosenduserpasswordtotheserver.AUserBPassCRetrDStor32.ThefunctionoftheadditionalheaderfieldinMIMEContent-Typeis.Atoconvertthemessagebodytoitsoriginnon-ASCIIformBtodeterminewhatactionsitshouldtakeonmessagebody6CtosendanE-mailtothereceivinguseragentD