计算机网络与通信期末考试B答案

四川考试试题（ B ）闭卷（2008 ——2009 学年第 2 学期）课程号：课序号：0 7 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：06 学生人数：印题份数：学号：姓名：8．) _B___ Is a protocol for transferring a file from one host toanother host.A. SMTP;B.FTP;C.TCP;D. UDP9．In TCP/IP stack, the transport layer ' s flow control mechanism uses BA) slow start B) congestion avoidanceC) three hand-shaking D) sliding window 10．Comparedw ith rdt2.0, the new service in rdt3.0 is to implement the reliable data transfer over the channel with BA)bit error B) data loss C) data transfer delayD) congestion11．ICMP control messages are transferred in D data unit.A) TCP B).UDP C).ARP D).IP12．The reliable data delivery between end systems is provided in the C layer of TCP/IP architecture.A) network layer B) data link layer C) transport layerD) session layer13．What is the main function of the network layer? ___AA. node-to-node delivery;B. process-to-processmessage deliveryC synchronization; D.updating and maintenance of routing tables14 ． Which IP address is ineffective ___D___ A) 202.131.45.61 B) 127.0.0.1 C) 192.168.0.215 ． If IP address is 198.108.126.66224, then subnet prefix is _C16 ． The output port of a router don __________________ 't perform __ C functions.A) the physical layer functions B) the data link layer functionsC) network management D) buffer management17 ．There are two broad classes of packet-switched networks: datagram networks and virtual-circuit networks. datagram networks forwardpackets in their switches use __B . A) MAC addresses B) IP addresses C) e-mail addresses D) virtual-circuitnumbers18 ．.as show below, which technology isn 't typical technongy. CA) digital subscriber line fiber-coaxial cableA) 198.108.126.60 B) 198.108.126.0 C) 198.108.126.64D) 198.108.126.224access networksB) hybridC)circuitswitchingD)wireless access19 ．Which layer-function is mostly implemented in an adapter (NIC )?domains.本页为第号：务必用 A4 纸打印三、填空题 （每空 1 分，共 20 分?）define format, order of messages sent and received among network entities, and actions taken on message transmission,receipt.2．The time required to examine the packet ' s header and determine whereA) physical layer and link layer B) network layer andtransport layerC) physical layer and network layer D) transportlayer and application layer 20 ． __AWhichd evice can ' t isolate the departmentalcollision A) Hub; B) switch;C)router;D)A and注： 1 试题字迹务必清晰，书写工整。

本题 4 页，题间不留空，一般应题卷分开教务处试题编1．_protocolsto direct the packet is part of the processing delay.3． Any network that forwards packets according to host destination4． Within the Internet the most important delays that packet suffered8． 10． A Web cache also called a _proxy__server__ 11． Suppose a user sitting in a home network behind host 10.0.0.1requests a Web page on some Web server Please according the NAT translation table at the NAT router. Fill in datagram that includeport numbers as well as IP addresses. （有 IP 缺端口号一个扣 0.5Dddr 分）④33451 分，共10 分）Dest addr=判断S =题___（___每___小__题__S addr= _________S addr= _________ D addr ________D addr= _________The top-down order7Interne t10.0.0.4addresses a _datagramnetwork.areprocessingdelay,queuingdelay,__propagation delay, and _transmissiondelay.5．Two important network-layer functioncan be identified: forwarding NAT transtation table WAN side LAN side 138.76.29.7, 10.0.0.1, 500133456． A link-layer address is variously called a address,or address,or7． Twog eneric forms of pipelined reliable date transfer protocols a re go-Back-Nand_ selective repeat,routinglan physicaMAC address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 纸打印五、计算题 (30 points)1. consider the following network. With the indicated link costs, use Dijkst10分wStep N 'D(x),p(x) D(V),p(v) D(U),p(u) D(y),p(y) D(t),p(t) D(s),1 W3,w1,w4,w ∞∞∞2 wv 3,w2,v4,v 8,v ∞3 wvu3,w4,v 5,u 7, 4 wvux4,v5,u 7, 5 wvuxy5,u7, 6wvuxyt6,7 wvuxyts最短路径： WX WV WVY WVU WVUT WVUTSshortest-path algorithm to compute the shortest path from Wt o all network n s2. Suppose, the ISP have been allocated the address block 197.23.18.0/24, now iISP want divide its address block into 6 equal-sized subnet address blocks, and subnet could include 28 hosts.1) Please utilize CIDRized addresses, determine the length of subnet po of address.(namely, how many bits should be extend?(2 points ) #' s network prefix(2 分) and subnetma 分)3) Please write out the subnet 1 4) Please write out the subnet 1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2) Please write out the subnet 1 #'s broadcast address.(2 分 )#'s range of host a ddress. (2 分)注： 1 试题字迹务必清晰，书写工整本题 4 页，注： 1 试题字迹务必清晰，书本题 4 页，写工整本页为第 4 页教务处试题编2 题间不留空，一般应题卷分开号：3 务必用A4 纸打印。