計(jì)算機(jī)網(wǎng)絡(luò)與通信期末考試_2009A_答案

1、四川大學(xué)期 考試試題A閉卷課程號(hào)：3030623030306230課序號(hào)：0 0 -7-7課程名稱：適用專業(yè)年級(jí)：0505學(xué)生人數(shù)：印題份數(shù):計(jì)算機(jī)網(wǎng)絡(luò)與通信 任課教師：等 成績: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)考試工作管理方法?和四川大學(xué)考場規(guī)那么? 。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)作弊處分條例?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)考試工作管理方法?、四川大學(xué)考場規(guī)那么?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)定及處理方法?進(jìn)行處理。第一題第二題第三

2、題第四題第五題總分二、單項(xiàng)選擇題每題l.l. 5 5分，共3030分7.protocol.A)SMTPB) POP3C)SNMPD) FTP8.As a data packet moves from the lower to the upper layers, headers are B(20212021學(xué)年第2學(xué)期、英譯漢1010分1. ADSL非對(duì)稱數(shù)字用戶線路DHCP動(dòng)態(tài)主機(jī)配置協(xié)議5.PDU協(xié)議數(shù)據(jù)單元IMAPInternet消息訪問協(xié)議地址解析協(xié)議2. Packet switching分組交換3.PPP點(diǎn)到點(diǎn)6. MIME用途互聯(lián)網(wǎng)郵件擴(kuò)展8. NAT網(wǎng)絡(luò)地址轉(zhuǎn)換9. ICMPInt

3、ernet控制信息協(xié)議4.7.10. ARP.6.is a Circuit-switched network.A. TDMB. Datagram network C. InternetThe store-and-forward delay is DA. processing delay B. queuing delay C. propagation delay D. transmission delayWhich is not the function of connection-oriented service? CA. flow controlB. congestion co

4、ntrol C. error correctionThe IP protocol lies in CA. application layer B. transport layer C. network layer D. link layerWhich of the following is the PDU for application layer_BA. datagram;B. message;bandwidth is described in _B_A) Bytes per secondC) megabits per millisecondD. virtual circuit networ

5、kD. reliable data transferC. frame;D. segmentB) Bits per secondD) centimetersA user who uses a user agent on his local PC receives his mail sited in a mail server by using _BD) sliding windowA)Added; B. subtracted; C. rearranged; D. modified9.In TCP/IP stack, the transport layer builds the connectio

6、n by _C一A) slow start B) negotiation C) three hand-shaking注：1試題字跡務(wù)必清晰，書寫工整。此題4頁，本頁為第1頁教務(wù)處試題編號(hào)：2題間不留空，一般應(yīng)題卷分開3務(wù)必用A4紙打印10.The main function of transport layer is to provide C data delivery.A) node to node B).point to point C).process to process D).neighbor to neighbor12 . The definition of reliable de

7、livery includes D .A). Error-free delivery B). Receipt of the complete messageC) In-order deliveryD). All of the above13.The traceroute is implemented with B messagesA) DNSB) ICMPC) ARPD) RIP14.Fragments which are smaller IP datagrams need to be reassemble at the BA) the destination routerB) the des

8、tination hostC) the next routerD) any router and host15. Which routing protocol is the defect of standard inter-AS routing protocol in todays Internet. _DA) RIPB) OSPFC) IGPD) BGP16.The virtual-circuit networks forward packets in their switches use _DA) MAC addressesB) IP addressesC)e-mail addresses

9、D) VC numbers17.packet-switching technologies that use virtual circuits include_D:A) X.25, IPB) X.25, frame relay.C) IPX, IPD) IP, TCP18.There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. datagram networksforward packets in their switches use _B.

10、A) MAC addressesB) IP addressesC) e-mail addressesD) virtual-circuit numbers19.if a host wants to emit a datagram to all hosts on the same subnet, then the datagramaddress is BA)B)C)In TCP/IP model, data units from application layer to data link layer are messagemessagesegmentD)datagramdatagramsegme

11、ntdatagrammessageframesegmentdatagramframeframemessage frame segmentstination IPA)C)54B) 55D) 20. Hub function is in thelayer.A)physical;B) data link;C) Network;D)a and b2題間不留空，一般應(yīng)題卷分開3務(wù)必用A4紙打印三、填空題每空1 1分，共2020分1.Internet provides both _ connection-ori

12、ented and connectionless services to applications2.Internet uses _ packet switching _rather than circuit-switching technology.3.Electronic mail including user agents mail servers and SMTP three major components.4.A process is identified by ip address as well as port number .5.Two important network-l

13、ayer function can be identified: forwarding , routing .6.Network layer services handle data transfer between hosts , transport layer services handle data transfer between processes7.An ARP request is broadcastto all host and an ARP reply is _unicast_ one host；8.A link-layer address is variously call

14、ed a _lan address, or physical address, or _MAC_address.9.Data link layer packet is frame10.Suppose that Host A has established a connection to a process in the server. Please fill in the segments containing data thatthe client and server hosts can send to each other.IfIf HostHost A A - HostHost B B

15、ThenThen HostHost A AHostHost B B四、判斷題每題1 1分，共1010分1.The internet applications such as SMTP, HTTP, TELNET us UDP, the internet s connectionless-oriented service F2.HTTP is mainly a push protocol and SMTP is mainly a pull protocol F3.The time required to propagate from the beginning of the link to a

16、router is the propagation delay T4.FTP send its control information out-of-band T5.link layer address is IP address F6.An ARP response sent within a frame with a specific destination MAC address T7.An IP address is technically associated with the host or router F8.A distance-vectorDValgorithm comput

17、es the least-cost path between a source and destination using complete, global knowledgeabout the network F9.Devices in a subnet can physically reach each other without intervening router T10. In packet-sw itched networks, a session s messages use the resources on demand, and Interne best effort to

18、deliver packetsin a timely manner T教務(wù)處試題編號(hào):Source port =1300Dest port =21Sequence number=1235Acknowledgment number=67905SYN=0ACKReceive windowChecksumNIL1000 bytes dataSource port =_21_Destport=_1300_Sequence number= 6790_Acknowledgment number=2235_5 SYN=0ACKReceive windowChecksumNIL1000 bytes datat

19、 makes its注：1試題字跡務(wù)必清晰，書寫工整。此題4頁，本頁為第2頁此題4頁，本頁為第3頁教務(wù)處試題編號(hào)：2題間不留空，一般應(yīng)題卷分開3務(wù)必用A4紙打印五、計(jì)算題(30(30 points)points)1. consider the following network. With the indicated link costs, use Dijkstra compute the shortest pathfrom W to all network nodes. 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(

20、s)1W3,w1,w4,woooooo2wv3,w2,v4,v8,voo3wvu3,w4,v5,u7,u4wvux4,v5,u7,u5wvuxy5,u7,u6wvuxyt6,t7wvuxyts最短路徑：WX WV WVY WVU WVUT WVUTS表格8分最短路徑2分2. Suppose a ISP has been allocated the address block /24, now if the ISP wants to divide its address block into6 equal-sized subnet address blocks, and each subnet could include 25 hosts.Please utilize CIDRized addresses, determine the length of subnet portion of address.(namely, how many bitsshould be extend?(2 Please write out the subnet 2# Pleasewrite out the subnet 2#Please write out t