四 川 大 学 期 末 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： 成绩： 适用专业年级：05 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 一、英译汉（10分） 1. ADSL非对称数字用户线路 2. Packet switching分组交换 3. PPP点到点 4. DHCP动态主机配置协议5. PDU协议数据单元 6. MIME用途互联网邮件扩展 7. IMAP Internet消息访问协议8. NAT 网络地址转换 9. ICMP Internet控制信息协议 10. ARP地址解析协议 二、单项选择题 （每小题l. 5分，共30分) 1． A is a Circuit-switched network. A. TDM B. Datagram network C. Internet D. virtual circuit network 2．The store-and-forward delay is D A. processing delay B. queuing delay C. propagation delay D. transmission delay 3．Which is not the function of connection-oriented service? C A. flow control B. congestion control C. error correction D. reliable data transfer 4．The IP protocol lies in C A. application layer B. transport layer C. network layer D. link layer 5．Which of the following is the PDU for application layer__B___ . A. datagram; B. message; C. frame; D. segment 6．bandwidth is described in _B__ A) Bytes per second B) Bits per second C) megabits per millisecond D) centimeters 7．A user who uses a user agent on his local PC receives his mail sited in a mail server by using _B___ protocol. A)SMTP B) POP3 C)SNMP D) FTP 8．As a data packet moves from the lower to the upper layers, headers are B . A)Added; B. subtracted; C. rearranged; D. modified 9．In TCP/IP stack, the transport layer builds the connection by C A) slow start B) negotiation C) three hand-shaking D) sliding window 第二题 第三题 第四题 第五题 总分 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 neighbor 11．In TCP/IP model, data units from application layer to data link layer are B . A) message?datagram?frame?segment B) message?segment?datagram?frame C) segment?datagram?frame?message D)datagram?message?frame?segment 12．The definition of reliable delivery includes D . A). Error-free delivery B). Receipt of the complete message C) In-order delivery D). All of the above 13．The traceroute is implemented with ___B_____ messages A) DNS B) ICMP C) ARP D) RIP 14．Fragments which are smaller IP datagrams need to be reassemble at the ___B_____ A) the destination router B) the destination host C) the next router D) any router and host 15．Which routing protocol is the defect of standard inter-AS routing protocol in today’s Internet. _D____ A) RIP B) OSPF C) IGP D) BGP 16．The virtual-circuit networks forward packets in their switches use _D_____. A) MAC addresses B) IP addresses C) e-mail addresses D) VC numbers 17．packet-switching technologies that use virtual circuits include__D_____: A) X.25, IP B) X.25, frame relay. C) IPX, IP D) IP, TCP 18．There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. datagram networks forward packets in their switches use _B_____. A) MAC addresses B) IP addresses C) e-mail addresses D) virtual-circuit numbers 19．.if a host wants to emit a datagram to all hosts on the same subnet, then the datagram’s destination IP address is _______B___________ A)255.255.255.0 B) 255.255.255.255 C)255.255.255.254 D) 127.0.0.1 20．Hub function is in the A layer. A)physical; B) data link; C) Network; D)a and b 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．Internet provides both __ connection-oriented and connectionless services to applications 2．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-layer function can be identified: forwarding , routing . 6．Network layer services handle data transfer between hosts , transport layer services handle data transfer between processes 7．An ARP request is broadcast __ to all host and an ARP reply is __unicast_ one host; 8．A link-layer address is variously called a _lan _address, or _physical_address, or __MAC_address. 9. Data link layer packet is frame 10．Suppose that Host A has established a connection to a process in the server. Please fill in the segments containing data that the client and server hosts can send to each other. Then Host A Host B If Host A Host B Source port =1300 Dest port =21 Source port =__21_ Dest port =_1300__ Sequence number=1235 Sequence number= 6790____ Acknowledgment number=6790 Acknowledgment number= 2235____ 5 SYN=0 ACK Receive window Checksum NIL 1000 bytes data 5 SYN=0 Checksum ACK Receive window NIL 1000 bytes data 四、判断题（每小题1分，共10分） 1．The internet applications such as SMTP, HTTP, TELNET us UDP, the internet’s connectionless-oriented service F 2．HTTP is mainly a push protocol and SMTP is mainly a pull protocol F 3．The time required to propagate from the beginning of the link to a router is the propagation delay T 4．FTP send its control information out-of-band T 5．link layer address is IP address F 6．An ARP response sent within a frame with a specific destination MAC address T 7．An IP address is technically associated with the host or router F 8．A distance-vector (DV) algorithm computes the least-cost path between a source and destination using complete, global knowledge about the network F 9．Devices in a subnet can physically reach each other without intervening router T 10．. In packet-switched networks, a session’s messages use the resources on demand, and Internet makes its best effort to deliver packets in a timely manner T 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