计算机网络与通信期末考试_毕业生.doc

四 川 大 学期 考 试 试 题（A）（200 200 学年第 2 学期）课程号：30306230 课序号：0 3 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： 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. TCP 2. SMTP 3.ISP 4.ICMP 5.OSPF6. CRC 7. CSMA/CD 8. ARP 9. DHCP 10.MTU 二、单项选择题 （每小题l分，共30分)1. The physical layer is concerned with the transmission of over the physical medium.A. Program; B. dialogs; C: protocols; D. bits2. As a data packet moves from the lower to the upper layers, headers are .A. Added; B. subtracted; C. rearranged; D. modified3. What is the main function of the transport layer?A. node-to-node delivery; B. process-to-process message deliveryC synchronization; D.updating and maintenance of routing tables4. Which of the following is the default mask for the address 01?A.; B.; C.; D.555. A router reads the address on a packet to determine the next hop.A. IP ; B. MAC; C. source; D.ARP6 . Bridges function is in the layer.A. physical; B. data link; C. network; D. A and B7. UDP needs the address to deliver the user datagram to the correct application program.A. port; B. application; C. internet; D. physical8. The definition of reliable delivery includes .A. Error-free delivery; B. Receipt of the complete messageC In-order delivery; D. All of the above9. At 100BASE-T,“T”is A. Fiber Optics B. baseband Coaxial cable C. broadband Coaxial cable D. Twisted-pair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 10. is not element of a protocol。A. words B. Syntax C. Semantics D. Timing 11. There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. The virtual-circuit networks forward packets in their switches use _. A) MAC addresses B) IP addresses C) e-mail addresses D) virtual-circuit numbers12 TCP service model doesnt provide _service. A) reliable transport service B) flow control service C) congestion-control service D) guarantee a minimum transmission rate service.13. The purpose of TCP port number is _ A)provide flow control B) provide congestion control C) identify the receiving process D) identify destination host . 14. A user who uses a user agent on his local PC receives his mail sited in a mail server by using _ protocol.A)SMTP B) POP3C)SNMP D)FTP15. Considering sliding-window protocol, if the size of the transmitted window is 1 and the size of the receiving window is 1,the protocol is A) stop-and-wait protocol B) Go-Back-N protocol C) selective Repeat protocol D) alternating-bit protocol16. which IP address is ineffective_.A) 1 B) C) D) 2217. if IP address is 3, subnet mask is ,then subnet prefix is_ A) B) C) 3 D)18.The traceroute is implemented with _messagesA) DNS B) ICMPC) ARP D) RIP19. Which layer-function is mostly implemented in an adapter（NIC）? _A) physical layer and link layer B) network layer and transport layerC)physical layer and network layer D) transport layer and application layer20. If a user brings his computer from chengdu to beijing, and accesses Internet again. Now, _ of his computer needs to be changed. A) MAC address B) IP addressC) e-mail address D) user address三、填空题 （每空1分，共20分）1.The Internet provides two services to its distributed applications: a connection-oriented service and a unreliable service.a. connectionless; b. reliable2. please fill in the types of delay in a router.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 A routerprocessingBA) processing delayB) queuingdelayC) transmissiondelayD) propagation delay3. please fill in encapsulate unit and internet protocol stackencapsulate unitMMMHtHtHnMHtHnHlmessage567 Application layer4In the layered architecture of computer networking, ( ) layer is the user of ( ) layer and the service provider of ( ) layer.A) nB) n+3C) n+1D) n-15.Among the Internet application protocols, ( ) protocol supports the Web service, ( ) protocol supports the Electronic mail, ( ) protocol supports the Internets directory service, ( ) protocol supports the remote file transfer.A) SMTPB) PPPC) TCPD) DNSE) FTPF) DHCPG) HTTP四、判断题（每小题1分，共10分）1. The size of the TCP RcvWindow never changes throughout the duration of the connection. ( ) 2. Any protocol that performs handshaking between the communication entities before transferring data is a connection-oriented service.3. A browser is a user agent for the Web.4. Socket is the programming interface between the application and the network5. FTP sends control information ”in-of-band”.6. It isnt possible for an application to enjoy reliable data transfer even when the application runs over UDP. 7. An ARP query is sent to all over the Internet. 8. MSS is the limit for the size of IP packet. 9. UDP is a kind of unreliable transmission layer protocol, so there is not any checksum field in UDP datagram header. 10 .Forwarding table is configured by both Intra and Inter-AS routing algorithm 五、计算题 (30 points) 1.Consider the following network. With the indicated link costs, use Dijkstras shortest-path algorithm to compute the shortest path from S to all network nodes.注：1试题字迹务必清晰，书写工整。 本题 4 页，本页为第 3 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 2tz 144y91162sv131x4u13wStepND(t),p(t)D(U),p(u)D(v),p(v)D(w),p(w)D(x),p(x)D(y),p(y)D(z),p(z)1s234567892. Suppose a ISP has been allocated the address block /24, now if the ISP wants to divide its address block into 6 equal-sized subnet address blocks, and each subnet could include 25 hosts.1) Please utilize CIDRized addresses, determine the length of subnet portion of address.(namely, how many bits should be extend?(2 分 )2) Please write out the subnet 2#s network prefix(2分) and subnet mask.(2分)3) Please write out the subnet 2#s broadcast