计算机网络与通信期末考试_2009A

四川大学期考试试题（A）闭卷（2008——2009学年第2学期）课程号：30306230课序号：07课程名称：计算机网络与通信任课教师：等成绩：适用专业年级：06学生人数：印题份数：学号：姓名：考试须知四川大学学生参加由学校组织或由学校承办的各级各类考试，必须严格执行《四川大学考试工作管理办法》和《四川大学考场规则》。有考试违纪作弊行为的，一律按照《四川大学学生考试违纪作弊处罚条例》进行处理。四川大学各级各类考试的监考人员，必须严格执行《四川大学考试工作管理办法》、《四川大学考场规则》和《四川大学监考人员职责》。有违反学校有关规定的，严格按照《四川大学教学事故认定及处理办法》进行处理。第一题第二题第三题第四题第五题总分一、英译汉（10分）1.ADSL2.Packetswitching3.PPP4.DHCP5.PDU6.MIME7.IMAP8.NAT9.ICMP10.ARP二、单项选择题（每小题l.5分，共30分)1．isaCircuit-switchednetwork.A.TDMB.DatagramnetworkC.InternetD.virtualcircuitnetwork2．Thestore-and-forwarddelayisA.processingdelayB.queuingdelayC.propagationdelayD.transmissiondelay3．Whichisnotthefunctionofconnection-orientedservice?A.flowcontrolB.congestioncontrolC.errorcorrectionD.reliabledatatransfer4．TheIPprotocolliesinA.applicationlayerB.transportlayerC.networklayerD.linklayer5．WhichofthefollowingisthePDUforapplicationlayer_____.A.datagram;B.message;C.frame;D.segment6．bandwidthisdescribedin___A)BytespersecondB)BitspersecondC)megabitspermillisecondD)centimeters7．AuserwhousesauseragentonhislocalPCreceiveshismailsitedinamailserverbyusing____protocol.A)SMTPB)POP3C)SNMPD)FTP8．Asadatapacketmovesfromthelowertotheupperlayers,headersare.A)Added;B.subtracted;C.rearranged;D.modified9．InTCP/IPstack,thetransportlayerbuildstheconnectionbyA)slowstartB)negotiationC)threehand-shakingD)slidingwindow10．Themainfunctionoftransportlayeristoprovidedatadelivery.A)nodetonodeB).pointtopointC).processtoprocessD).neighbortoneighbor11．InTCP/IPmodel,dataunitsfromapplicationlayertodatalinklayerare.A)messagedatagramframesegmentB)messagesegmentdatagramframeC)segmentdatagramframemessageD)datagrammessageframesegment12．Thedefinitionofreliabledeliveryincludes.A).Error-freedeliveryB).ReceiptofthecompletemessageC)In-orderdeliveryD).Alloftheabove13．Thetracerouteisimplementedwith________messagesA)DNSB)ICMPC)ARPD)RIP14．FragmentswhicharesmallerIPdatagramsneedtobereassembleatthe________A)thedestinationrouterB)thedestinationhostC)thenextrouterD)anyrouterandhost15．Whichroutingprotocolisthedefactostandardinter-ASroutingprotocolintoday’sInternet._____A)RIPB)OSPFC)IGPD)BGP16．Thevirtual-circuitnetworksforwardpacketsintheirswitchesuse______.A)MACaddressesB)IPaddressesC)e-mailaddressesD)VCnumbers17．packet-switchingtechnologiesthatusevirtualcircuitsinclude_______:A)X.25,IPB)X.25,framerelay.C)IPX,IPD)IP,TCP18．Therearetwobroadclassesofpacket-switchednetworks:datagramnetworksandvirtual-circuitnetworks.datagramnetworksforwardpacketsintheirswitchesuse______.A)MACaddressesB)IPaddressesC)e-mailaddressesD)virtual-circuitnumbers19．.ifahostwantstoemitadatagramtoallhostsonthesamesubnet,thenthedatagram’sdestinationIPaddressisA)255.255.255.0B)255.255.255.255C)255.255.255.254D)127.0.0.120．Hubfunctionisinthelayer.A)physical;B)datalink;C)Network;D)aandb注：1试题字迹务必清晰，书写工整。本题4页，本页为第1页2题间不留空，一般应题卷分开教务处试题编号：3务必用A4纸打印三、填空题（每空1分，共20分）1．Internetprovidesboth_______andconnectionlessservicestoapplications2．Internetuses_______ratherthancircuit-switchingtechnology.3．Electronicmailincluding,SMTPthreemajorcomponents.4.Aprocessisidentifiedby,aswellas.5．Twoimportantnetwork-layerfunctioncanbeidentified:_____,____.6．Networklayerserviceshandledatatransferbetween,transportlayerserviceshandledatatransferbetween7．AnARPrequestis__toallhostandanARPreplyis_________onehost;8．Alink-layeraddressisvariouslycalleda________address,or________address,or________address.9.Datalinklayerpacketis10．SupposethatHostAhasestablishedaconnectiontoaprocessintheserver.Pleasefillinthesegmentscontainingdatathattheclientandserverhostscansendtoeachother.四、判断题（每小题1分，共10分）1．TheinternetapplicationssuchasSMTP,HTTP,TELNETusUDP,theinternet’sconnectionless-orientedservice2．HTTPismainlyapushprotocolandSMTPismainlyapullprotocol3．Thetimerequiredtopropagatefromthebeginningofthelinktoarouteristhepropagationdelay4．FTPsenditscontrolinformationout-of-band5．linklayeraddressisIPaddress6．AnARPresponsesentwithinaframewithaspecificdestinationMACaddress7．AnIPaddressistechnicallyassociatedwiththehostorrouter8．Adistance-vector(DV)algorithmcomputestheleast-costpathbetweenasourceanddestinationusingcomplete,globalknowledgeaboutthenetwork9．Devicesinasubnetcanphysicallyreacheachotherwithoutinterveningrouter10．.Inpacket-switchednetworks,asession’smessagesusetheresourcesondemand,andInternetmakesitsbestefforttodeliverpacketsinatimelymannerSourceport=1300Destport=21Sequencenumber=1235Acknowledgmentnumber=67905SYN=0ACKReceivewindowChecksumNIL1000bytesdataSourceport=_______Destport=______Sequencenumber=____Acknowledgmentnumber=____5SYN=0ACKReceivewindowChecksumNIL1000bytesdata注：1试题字迹务必清晰，书写工整。本题4页，本页为第2页2题间不留空，一般应题卷分开教务处试题编号：3务必用A4纸打印IfHostAHostBThenHostAHostB五、计算题(30points)1.considerthefollowingnetwork.Withtheindicatedlinkcosts,useDijkstra’sshortest-pathalgorithmtocomputetheshortestpathfromWtoallnetworknodes.10分StepN’D(x),p(x)D(V),p(v)D(U),p(u)D(y),p(y)D(t),p(t)D(s),p(s)1W2345672.SupposeaISPhasbeenallocatedtheaddressblock202.12.168.0/24,nowiftheISPwantstodivideitsaddressblockinto6equal-sizedsubnetaddressblocks,andeachsubnetcouldinclude2