計算機網絡與通信期末考試B答案

1、大學期考試試題（B）閉卷（200820W第2學期）課程號：課序號：07課程名稱：計算機網絡與通信任課教師:等成績：適用專業(yè)年級：06學生人數(shù)：印題份數(shù)：學號：姓名：考試須知四川大學學生參加由學校組織或由學校承辦的各級各類考試，必須嚴格執(zhí)行四川大學考試工作管理辦法和四川大學考場規(guī)則有考試違紀作弊行為的，一律按照四川大學學生考試違紀作弊處罰條例進行處理。四川大學各級各類考試的監(jiān)考人員，必須嚴格執(zhí)行四川大學考試工作管理辦法、四川大學考場規(guī)則和四川大學監(jiān)考人員職責有違反學校有關規(guī)定的，嚴格按照四J11大學教學事故認定及處理辦法進行處理。第一題第二題第三題第四題第五題卜總分一、英譯漢（10分）ISPIN

2、TERT服務供應商2.NIC網絡接口卡3.DNS域名服務系統(tǒng)4.MAC介質接入控制5BGP邊界網關協(xié)議6.MSS最大數(shù)據(jù)段尺寸7.FTP文件傳輸協(xié)議8MPLS多協(xié)議標簽交換9AS自治系統(tǒng)1O.packetswitching分組交換:、單項選擇題（每小題I.5分，共30分）Werefertothelink-layerpacketsasDC. datagrams D. framesA.messagesB.segmentsTheIPprotocolliesinCA.applicationlayerB.transportlayerC.networklayerD.linklayerAisaCircuit

3、-switchednetwork.A.TDMB.DatagramnetworkC.InternetD.virtualcircuitnetworkThepacketexperiencesaBdelayasitwaitstobetransmittedontothelink.A.processingdelayB.queuingdelayC.propagationdelayD.transmissiondelayDWhichthefollowingprotocolsdoesnotuseTCP/IPasitsunderlyingprotocols?A.SMTP;B.FTP;C.TELNET;D.TFTPW

4、hatisusedtospecifyplacementoftext,filesandobjectsthataretobetransferredfromthewebservertotheclient?BA.HTTPB.HTMLC.HDLCD.AlloftheabovebandwidthisdescribedinBA)BytespersecondB)BitspersecondC)megabitspermillisecondD)centimeters)_BIsaprotocolfortransferringafilefromonehosttoanotherhost.A. SMTP; B.FTP;C.

5、TCP;D. UDPInTCP/IPstack,thetransportlayers flow control mechanisBA)slowstartB)congestionavoidaneeC)threehand-shakingD)slidingwindowComparedwithrdt2.0,thenewserviceinrdt3.0istoimplementthereliabledatatransferoverthechannelwithBA)biterrorB)datalossC)datatransferdelayD)congestionICMPcontrolmessagesaret

6、ransferredinDdataunit.A)TCPB).UDPC).ARPD).IPThereliabledatadeliverybetweenendsystemsisprovidedintheClayerofTCP/IParchitecture.A)networklayerB)datalinklayerC)transportlayerD)sessionlayerWhatisthemainfunctionofthenetworklayer?AA.node-to-nodedelivery;B.process-to-processmessagedeliveryD.updati ng andsy

7、nchronization;maintenanceofroutingtablesB)B) D) 24 t perform functions.WhichIPaddressisineffectiveDA)1C)ifipaddressis6224,thensubnetprefixis_CA)0C).theoutputportofarouterdonA)thephysicallayerfunctionsB)thedatalinklayerfunctionsC)networkmanagementD)buffermanagement.therearetwobroadclassesofpacket-swi

8、tchednetworks:datagramnetworksandvirtual-circuitnetworks.datagramnetworksforwardpacketstheirswitchesuseBA)MACaddressesC)e-mailaddresses.asshowbelow,whichtechnologyisntechnongy.Cdigitalsubscriberlinefiber-coaxialcableIPaddressesD)virtual-circuitnumbersttypicalaccessnetworksB)hybridC)circuitswitchingD

9、)wirelessaccessWhichlayer-functionismostlyimplementedinanadapter(NICA_A)physicallayerandlinklayerB)networklayerandtransportlayerC)physicallayerandnetworklayerD)transportlayerandapplicationlayerAWhichdevicecantisolatethedepartmentalcollisiondomains.A)Hub;B)switch;C)router;D)AandB注：1試題字跡務必清晰，書寫工整。本題4頁

10、，本頁為第1頁2題間不留空，一般應題卷分開教務處試題編號：3務必用A4紙打印三、填空題(每空1分，共20分?)_protocolsdefineformat,orderofmessagessentandreceivedamongnetworkentities,andactionstakenonmessagetransmission,receipt.Thetimerequiredtoexaminethepacketsheaderanddeterminewheretodirectthepacketispartoftheprocessingdelay.Anynetworkthatforwardspac

11、ketsaccordingtohostdestinationaddressesa_datagramnetwork.WithintheInternetthemostimportantdelaysthatpacketsufferedare_processingoutingdelay,queuingdelay,_propagation.delay,and_transmission,delay.5.Twoimportantnetwork-layerfunctioncanbeidentified:forwarding6.Aaddress,or.physiaddress,or_MACaddress.and

12、selectiverepeat8.10.AWebcachealsocalleda_proxyserver7.Twogenericformsofpipelinedreliabledatetransferprotocolsarego-Back-N11.SupposeausersittinginahomenetworkbehinchostrequestsaWebpageonsomeWebserverPleaseaccordingtheNATtranslationtableattheNATrouter.Fillindatagramthatinclude3345判斷題（每小題1分，t10分）DddrTh

13、etop-downorderoftheinternDestaddr=0.0.4addr=addr=TheinternetscohnectionlessservicemakesprovisionforflbwcontrolportnumbersaswellasIPaddresses(有IP缺端口號個扣0.5分)andcongestioncontrol(F)3.他ARPresponsesentwithinaframewithaspecificdestinationIPaddress(F)linklayeraddressislanaddress(t)heSocketistheprogrammingi

14、nterfacebetweentheapplicationlayerandtnetworklayer(F)Routinginvolvesallofanetwork(T)sroutersForwardingtableisconfiguredbybothIntraandInter-ASroutingalgorithm(N)esAnynetworkthatforwardspacketsaccordingtohostdestinationaddressisaVCnetwork(F)HTTPismainlyapushprotocolandSMTPismainlyapullprotocol(N)Theba

15、sicserviceoflinklayeristomoveanetwork-layerdatagramfromonenode(routerorhost)to本題4教務處anadjacentnode.(N)注：1試題字跡務必清晰，書寫工整。頁，本頁為第2頁2題間不留空，一般應題卷分開試題編號：3務必用A4紙打印五、計算題(30points)considerthefollowingnetwork.Withtheindicatedlinkcosts,useDijkstrashortest-pathalgorithmtocomputetheshortestpathfromWtoallnetworkno

16、des.10分twStepND(x),p(x)D(V),p(v)D(U),p(u)D(y),p(y)D(t),p(t)D(s),p(s)1W3,w1,w4,woooooo2wv3,w2,v4,v8,voo3wvu3,w4,v5,u7,u4wvux4,v5,u7,u5wvuxy5,u7,u6wvuxyt6,t7wvuxyts最短路徑：WXWVWVYWVUWVUTWVUTSSuppose,theISPhavebeenallocatedtheaddressblock/24,nowiftheISPwantdivideitsaddressblockinto6equal-sizedsubnetaddres

17、sblocks,andeachsubnetcouldinclude28hosts.PleaseutilizeCIDRizedaddresses,determinethelengthofsubnetportionofaddress.(namely,howmanybitsshouldbeextend?(2points)Pleasewriteoutthesubnet1#snetworkprefix(2分)andsubnetmask.(2分)Pleasewriteoutthesubnet#sbroadcastaddress.(分)4) Please write out the sub net #s range of hostaddress. (2 分)注：1試題字跡務必清晰，