计算机网络原理期末试题复习总结.docx

1、计算机网络原理期末试题复习总结1Ethernet使用的MAC协议是（1）。当发生冲突时，将进入二进制指数退避阶段，对于第3次冲突，等待重传的最长时间是512位时间的（2）倍。（1）AALOHA BCSMA/CD CCSMA/CA DCSMA/DD （2）A1 B3C5 D72网络体系结构定义计算机网络的分层结构，TCP/IP模型和ISO/OSI参考模型是两个主要的网络模型，其中TCP/IP协议传送层之上的层是（3）层，而ISO/OSI 则是一个（4）层的模型。（3）A应用B表述C会话D网络（4）A4 B5 C6 D73传统的以太网传输介质是同轴电缆，其中使用粗同轴电缆的网络称为（5）网络，使用

2、细同轴电缆的网络称为（6）网络。10Base-T网络使用的传输介质是无屏蔽双绞线，简称为（7）。（5）A5BASE B10BASE-10 C10BASE-5D10BASE-2 （6）A5BASE B10BASE-10 C10BASE-5 D10BASE-2（7）AUPT BUTP CUPP DUUP 4有N个节点共享一条总传输速率为R的通信信道，若采用TDMA协议，则每个节点的平均传输速率是（8），而瞬时传输速率则为（9）；如果采用FDMA 协议，则每个节点的平均传输为（10），而瞬时传输速率则为（11）。（8）AR BR/N CNR D2R（9）AR BR/N CNR D2R（10）AR B

3、R/N CNR D2R（11）AR BR/N CNR D2R5可靠传输协议rdt3.0的发送和接收窗口都是1，对其进行改进后的GBN协议和SR协议都把发送窗口尺寸扩大为N（1）。但GBN协议的接收窗口为（12），而SR协议的接收窗口为（13）。对SR协议，若使用k位的序号，则其发送窗口尺寸应（14）。（12）A1 BN/4 CN/2 DN（13）A1 BN/4 CN/2 DN（14）A不大于2k B等于2k C不大于2k-1D等于2k-16PPP协议可以用在（15）链路上，并使用（16）协议完成链路状态的管理，使用（17）协议完成网络层地址配置和压缩方式协商。（15）A多点对多点B点对点C点对

4、多点D任何（16）ACNP BPLC CLCP DNCP（17）ACNP BPLC CLCP DNCP 7RTP协议和RTCP协议是TCP/IP协议的（18）层的扩充子层，H.323是（19）层协议。（18）A应用层B传送层C网络层D链路层（19）A应用层B传送层C网络层D链路层8在以太网中，增加帧的尺寸将使信道利用率（20）。（20）A提高B降低C保持恒定D无法断定二、Match the following tasks to one of the TCP/IP layers: (10%)1.Route determination ( 网络层)2.Transmission of Segment

5、 ( 运输层)3.ASCII changed to EBCDIC (链路层)4.Frame defined （链路层)5.Transmission of data frame ( 链路层)6.Provides log-in and logout procedures （应用程)7.Selects a destination network (网络层)8.Provides services for the network applications (应用层)9.Reliable end-to-end data transmission （运输层)10.Provides E-mail and fi

6、le transfer services （应用程)三、Answer the following questions (20%)：（1）Please show an example for every IP V4 address classes. (5%)A类地址范围(0.0.0.0-127.255.255.255)B类地址范围(128.0.0.0-191.255.255.255)C类地址范围(192.0.0.0-223.255.255.255)D类地址范围(224.0.0.0-239.255.255.255)E类地址范围(240.0.0.0-255.255.255.255)（2）Consid

7、er IP address 202.203.208.68 . What are the broadcast address and network address when default network mask is used? (5%)broadcast address :202.203.208.255network address :202.203.208.0（3）What are the format and example of IPv6 address?(5%)(4)Consider plain text “thisisatest” , and the Caesar cipher

8、 of k=4 is used. What is theCipher text after encrypting? (5%)四、Complete follow problems. (35%)1.Suppose we want to transmit the message 10101001 and protect it from errors usingthe CRC generator x3+1. Use long division to determine the message that should be transmitted.（10%）2. Consider a CSMA/CD n

9、etwork running at 100Mbps, over a 1000m cable with norepeaters. The signal speed in the cable is 2108m/sec. What is the minimum frame size for check collision reliably? （10%3. Suppose two Ethernet nodes of 10Mbps, A and B, are attached to opposite ends of a900m cable, and there are 4 repeaters betwe

10、en A and B. If the size of frame is 1000 bits, and the signal propagation speed is 2108m/s, and each repeater inserts 20-bit delay.(15%)(1) What is the one-way propagation delay (including repeater delays) between A andB in second ?(2) How long time is node As a frame completely delivered at node B?

11、五、Consider a LAN shown below and one class C address 202.1.0.0/24 is available only. Please accomplish the following questions: (15%)(1)Assign IP Network number and netmask for all LANs.(2)Assign IP addresses toall network interfaces .(3)Determine the route tableon router R1.R113A BHUBC DHUB2R212Ans

12、wer:（1）网络地址分配网络网络地址网络掩码A、B、R1-1 202.1.1.0/26 255.255.255.0C、D、R1-2 202.1.1.64/26 255.255.255.0R1-3、R2-1 202.1.1.128/26 255.255.255.0E、F、R2-2 202.1.1.192/26 255.255.255.0（2）端口IP地址分配端口IP地址端口IP地址端口IP地址A 202.1.1.2 C 202.1.1.65 E 202.1.1.193B 202.1.1.1 D 202.1.1.66 F 202.1.1.194R1-1 202.1.1.63 R1-2 202.1

13、.1.126 R2-2 202.1.1.254R1-3 202.1.1.190 R2-1 202.1.1.189（3）R1上的路由表Dest. Network next router N hops Interface三、Answer follow questions.(20%)（1）How big is the Ethernet address space? The IPv4 address space? (5%)（2）Compare and contrast link-state and distance-vector routing algorithm.(5%)（3）For a commu

14、nication session between two hosts, which host is the client and which is the server?(5%)（4）Consider c ipher text “wklvlvdwhvw” , and the Caesar cipher of k=3 is used. What isthe plain text accordingly? (5%)五、Complete follow problems. (35%)1. Suppose we want to transmit the message 10110001. Find th

15、e CRC field of packet that should be transmitted when generator x3+x+1 is used. (10%)2. Suppose the round-trip propagation delay for ETHERNET is 51.2s. This yields aminimum packet size of 64 bytes. What is the minimum packet size if the delay time held constant (i.e. 51.2s) when the transmission rate rises to 100Mbps? Why? (10%) 2.Suppose two Ethernet nodes of 10Mbps, A and B, are attached to opposite ends of a900m cable, and there are 4 repeaters between A and B. If the size of frame is