計(jì)算機(jī)網(wǎng)絡(luò)與通信期末考試B答案

1、四 川 大學(xué)期 考 試試題（B ） 閉卷（2008 2009 學(xué)年第 2 學(xué)期）課程號(hào)：課序號(hào)：0 7課程名稱：計(jì)算機(jī)網(wǎng)絡(luò)與通信 任課教師：等成績(jī)：適用專業(yè)年級(jí)：06 學(xué)生人數(shù)： 印題份數(shù)： 學(xué)號(hào)：姓名：考試須知四川大學(xué)學(xué)生參加由學(xué)校組織或由學(xué)校承辦的各級(jí)各類考試，必須嚴(yán)格執(zhí)行四川大學(xué)考試工作 管理辦法和四川大學(xué)考場(chǎng)規(guī)則 。有考試違紀(jì)作弊行為的，一律按照四川大學(xué)學(xué)生考試違紀(jì)作 弊處罰條例進(jìn)行處理。四川大學(xué)各級(jí)各類考試的監(jiān)考人員，必須嚴(yán)格執(zhí)行四川大學(xué)考試工作管理辦法、四川大學(xué)考場(chǎng)規(guī)則和四川大學(xué)監(jiān)考人員職責(zé)。有違反學(xué)校有關(guān)規(guī)定的，嚴(yán)格按照四川大學(xué)教學(xué)事故認(rèn)定及處理辦法進(jìn)行處理。第一題 第二題 第三

2、題 第四題 第五題 總分一、英譯漢（10分）1. ISP INTERT服務(wù)供應(yīng)商 2.NIC網(wǎng)絡(luò)接口卡3. DNS 域名服務(wù)系統(tǒng) 4.MA資質(zhì)接入控制5 BGP邊界網(wǎng)關(guān)協(xié)議6. MSS最大數(shù)據(jù)段尺寸 7. FTP文件傳輸協(xié)議8 MPLS多協(xié)議標(biāo)簽交換 9 AS自治系統(tǒng) 10. packet switching 分組交換二、單項(xiàng)選擇題 （每小題l. 5分，共30分）D. We refer to the link-layer packets as D D.A. messagesB. segments C. datagramsframes. The IP protocol lies inCA. ap

3、plication layerB. transport layer C. networklayer D. link layer. A is a Circuit-switched network.A. TDMB. Datagram network C. InternetD.virtual circuit network. The packet experiences a B delay as it waits to be transmitted onto the link.A. processing delay B. queuing delay C. propagation delay D. t

4、ransmission delay. DWhich the following protocols does not use TCP/IP as its underlying protocols?A. SMTP; B.FTP; C.TELNET; D.TFTPWhat is used to specify placement of text, files and objectsthat are to be transferred from the web server to the client?BA. HTTP B.HTML C.HDLC D. All of the above7 . ban

5、dwidth is described in _B_A) Bytes per secondB) Bits per secondC) megabits per millisecond D) centimeters) _B Is a protocol for transferring a file from one host toanother host. SMTP; B.FTP; C.TCP; D. UDP. In TCP/IP stack, the transport layer s flow control mechanism uses _BA) slow start B) congesti

6、on avoidanceC) three hand-shaking D) sliding window. Comparedwith rdt2.0, the new service in rdt3.0 is to implement the reliable data transfer over the channel with B A)bit errorB) data lossC) data transfer delayD) congestion. ICMP control messages are transferred in D data unit.A) TCP B).UDP C).ARP

7、 D).IP. The reliable data delivery between end systems is provided inthe C layer of TCP/IP architecture.A) network layer B) data link layerC) transport layerD) session layer. What is the main function of the network layer? A A. node-to-node delivery;B. process-to-processmessage deliveryC synchroniza

8、tion;D.updating and maintenance of routing tables. Which IP address is ineffective DA) 1B) C) . If IP address is 6224, then subnet prefix is _CA) 0B) A) 0B) C) 4D) 24C) 4D) 24. The output port of a router don t perform _ C functions.A) the physical layer functionsB) the data linklayer functionsC) ne

9、twork managementD) buffermanagement. There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. datagram networks forwardpackets in their switches use _BMAC addressesIP addressese-mail addressesD) virtual-circuitMAC addressesIP addressese-mail addressesD

10、) virtual-circuitnumbers18 . .as show below, which technology isn t typicalaccessnetworks18 . .as show below, which technology isn t typicalaccessnetworkstechnongy. CA) digital subscriber linetechnongy. CA) digital subscriber linefiber-coaxial cableB) hybridC)circuitswitchingC)circuitswitchingD)wire

11、less access. Which layer-function is mostly implemented in an adapter (NIC) ? _AA) physical layer and link layer B)network layer andtransport layerC) physical layer and network layer D) transportlayer and application layer. A Whichdevice can t isolate the departmental collision domains.A) Hub; B) sw

12、itch; C) router; D) A and B注：1試題字跡務(wù)必清晰，書寫工整。本題4 頁，本頁為第1 頁題間不留空，一般應(yīng)題卷分開教務(wù)處試題編號(hào)：務(wù)必用A4紙打印三、填空題(每空1分，共20分？)protocols define format, order of messagessent and received among network entities, and actions taken on message transmission,receipt.The time required to examine the packet s header and determine

13、where to direct the packet is part of the _processing delay.Any network that forwards packets according to host destinationaddresses a _work.addresses a _work.Within the Internet the most important delays that packet cessing.delay,queuingdelay,_propagationdelay,and transmissiondelay.Twoimportant net

14、work-layer functioncan be identified: forwardingNAT transtation tableWAN sideLAN side,5001,3345,routinglanphysicalMACaddress.A link-layer address is variously called aaddress,cessing.delay,queuingdelay,_propagationdelay,and transmissiondelay.Twoimportant network-layer functioncan be identified: forw

15、ardingNAT transtation tableWAN sideLAN side,5001,3345,routinglanphysicalMACaddress.A link-layer address is variously called aaddress,oraddress,orTwogeneric forms ofpipelined reliable date transfer protocolsarego-Back-Nand selective repeat8. 10. A Web cache also called a _proxy_server_ 11. Suppose a

16、user sitting in a home network behind host requests a Web page on some Web server Please according the NATtranslation table at the NAT router. Fill in datagram that includeport numbers as well as IP addresses.（有 IP 缺端口號(hào)個(gè)扣 0.5S addr=D addr判斷題（每小題1S addr=D addr判斷題（每小題1分，共10分） Dddr3345Dest addr=Th。top

17、down orderInternetprotocQ 小 3 小S addr=_D addr=application, network, transport, link, physical layers (F)The internet s connectionless service makes provision for flowcontrol and congestion control (F)An ARP response sent within a frame with a specific destinationIP address (F)link layer address is L

18、AN address (T)Socket is the programming interface between the application layer and the network layer (F)Routing involves all of a network s routers (T)Forwarding table is configured by both Intra and Inter-AS routing algorithm (N)Any network that forwards packets according to host destination addre

19、sses is a VC network (F)HTTPis mainly a push protocol and SMTPs mainly a pull protocol (N)The basic service of link layer is to movea network-layer datagram from one node (router or host ) to an adjacent node. (N)注：1試題字跡務(wù)必清晰，書寫工整。本題4 頁，本頁為第2 頁題間不留空，一般應(yīng)題卷分開教務(wù)處試題編號(hào):務(wù)必用A4紙打印五、計(jì)算題(30 points)consider the

20、 following network. With the indicated link costs, use Dijkstshortest-pathalgorithm to compute the shortestpath from Wto all network rshortest-pathalgorithm to compute the shortestpath from Wto all network r10分ttwStepN，D(x),p(x)D(V),p(v)D(U),p(u)D(y),p(y)D(t),p(t)D(s),1W3,w1,w4,wooooQ2wv3,w2,v4,v8,vQ3wvu3,w4,v5,u7,4wvux4,v5,u7,5wvuxy5,u7,6wvuxyt6,7wvuxyts最短路徑：WX WV WVY WVU WVUT WVUTSSuppose, the ISP have been allocated the address block /24, now i ISP want divide its address block into 6 equal-sized subnet address blocks, and subnet could include