计算机网络原理期末试题复习总结.docx
《计算机网络原理期末试题复习总结.docx》由会员分享,可在线阅读,更多相关《计算机网络原理期末试题复习总结.docx(7页珍藏版)》请在冰豆网上搜索。
计算机网络原理期末试题复习总结
1.Ethernet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)A.ALOHAB.CSMA/CDC.CSMA/CAD.CSMA/DD
(2)A.1B.3C.5D.7
2.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)A.4B.5C.6D.7
3.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)A.5BASEB.10BASE-10C.10BASE-5D.10BASE-2(6)A.5BASEB.10BASE-10C.10BASE-5D.10BASE-2(7)A.UPTB.UTPC.UPPD.UUP4.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)A.RB.R/NC.NRD.2R
(9)A.RB.R/NC.NRD.2R
(10)A.RB.R/NC.NRD.2R
(11)A.RB.R/NC.NRD.2R
5.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)A.1B.N/4C.N/2D.N
(13)A.1B.N/4C.N/2D.N
(14)A.不大于2kB.等于2kC.不大于2k-1D.等于2k-1
6.PPP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.点对多点D.任何
(16)A.CNPB.PLCC.LCPD.NCP
(17)A.CNPB.PLCC.LCPD.NCP7.RTP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、MatchthefollowingtaskstooneoftheTCP/IPlayers:
(10%)
1.Routedetermination(网络层)
2.TransmissionofSegment(运输层)
3.ASCIIchangedtoEBCDIC(链路层)
4.Framedefined(链路层)
5.Transmissionofdataframe(链路层)
6.Provideslog-inandlogoutprocedures(应用程)
7.Selectsadestinationnetwork(网络层)
8.Providesservicesforthenetworkapplications(应用层)
9.Reliableend-to-enddatatransmission(运输层)
10.ProvidesE-mailandfiletransferservices(应用程)
三、Answerthefollowingquestions(20%):
(1)PleaseshowanexampleforeveryIPV4addressclasses.(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)ConsiderIPaddress202.203.208.68.Whatarethebroadcastaddressandnetworkaddresswhendefaultnetworkmaskisused?
(5%)
broadcastaddress:
202.203.208.255
networkaddress:
202.203.208.0
(3)WhataretheformatandexampleofIPv6address?
(5%)
(4)Considerplaintext“thisisatest”,andtheCaesarcipherofk=4isused.Whatisthe
Ciphertextafterencrypting?
(5%)
四、Completefollowproblems.(35%)
1.Supposewewanttotransmitthemessage10101001andprotectitfromerrorsusing
theCRCgeneratorx3+1.Uselongdivisiontodeterminethemessagethatshouldbetransmitted.(10%)
2.ConsideraCSMA/CDnetworkrunningat100Mbps,overa1000mcablewithno
repeaters.Thesignalspeedinthecableis2×108m/sec.Whatistheminimumframesizeforcheckcollisionreliably?
(10%
3.SupposetwoEthernetnodesof10Mbps,AandB,areattachedtooppositeendsofa
900mcable,andthereare4repeatersbetweenAandB.Ifthesizeofframeis1000bits,andthesignalpropagationspeedis2×108m/s,andeachrepeaterinserts20-bitdelay.
(15%)
(1)Whatistheone-waypropagationdelay(includingrepeaterdelays)betweenAand
Binsecond?
(2)HowlongtimeisnodeA’saframecompletelydeliveredatnodeB?
五、ConsideraLANshownbelowandoneclassCaddress202.1.0.0/24isavailableonly.Pleaseaccomplishthefollowingquestions:
(15%)
(1)AssignIPNetworknumberandnetmaskforallLANs.
(2)AssignIPaddressesto
allnetworkinterfaces.
(3)Determinetheroutetable
onrouterR1.
R1
1
3
AB
HUB
CD
HUB
2
R2
1
2
Answer:
(1)网络地址分配
网络网络地址网络掩码
A、B、R1-1202.1.1.0/26255.255.255.0
C、D、R1-2202.1.1.64/26255.255.255.0
R1-3、R2-1202.1.1.128/26255.255.255.0
E、F、R2-2202.1.1.192/26255.255.255.0
(2)端口IP地址分配
端口IP地址端口IP地址端口IP地址
A202.1.1.2C202.1.1.65E202.1.1.193
B202.1.1.1D202.1.1.66F202.1.1.194
R1-1202.1.1.63R1-2202.1.1.126R2-2202.1.1.254
R1-3202.1.1.190R2-1202.1.1.189
(3)R1上的路由表
Dest.NetworknextrouterNhopsInterface
三、Answerfollowquestions.(20%)
(1)HowbigistheEthernetaddressspace?
TheIPv4addressspace?
(5%)
(2)Compareandcontrastlink-stateanddistance-vectorroutingalgorithm.(5%)
(3)Foracommunicationsessionbetweentwohosts,whichhostistheclientandwhichistheserver?
(5%)
(4)Considerciphertext“wklvlvdwhvw”,andtheCaesarcipherofk=3isused.Whatis
theplaintextaccordingly?
(5%)
五、Completefollowproblems.(35%)
1.Supposewewanttotransmitthemessage10110001.FindtheCRCfieldofpacketthatshouldbetransmittedwhengeneratorx3+x+1isused.(10%)
2.Supposetheround-trippropagationdelayforETHERNETis51.2μs.Thisyieldsa
minimumpacketsizeof64bytes.Whatistheminimumpacketsizeifthedelaytimeheldconstant(i.e.51.2μs)whenthetransmissionraterisesto100Mbps?
Why?
(10%)2.SupposetwoEthernetnodesof10Mbps,AandB,areattachedtooppositeendsofa
900mcable,andthereare4repeatersbetweenAandB.Ifthesizeofframeis