计算机网络英文题库

1、Chapter 5 The Link Layer and Local Area Network1A ( ) protocol is used to move a datagram over an individual link.Aapplication-layerBtransport-layerCnetwork-layerDlink-layer2The units of data exchanged by a link-layer protocol are called ( ).AdatagramsBframesCsegments Dmessages3Which of the followin

2、g protocols is not a link-layer protocol? ( )AEthernetBPPPCHDLCDIP4In the following four descriptions, which one is not correct? ( )Alink-layer protocol has the node-to-node job of moving network-layer datagrams over a single link in the path.BThe services provided by the link-layer protocols may be

3、 different.CA datagram must be handled by the same link-layer protocols on the different links in the path.DThe actions taken by a link-layer protocol when sending and receiving frames include error detection, flow control and random access.5Which of the following services can not offered by a link-

4、layer protocol? ( )Acongestion controlBLink AccessCError controlDFraming6( ) protocol serves to coordinate the frame transmissions of the many nodes when multiple nodes share a single broadcast link.AARPBMACCICMPDDNS7In the following four descriptions about the adapter, which one is not correct? ( )

5、AThe adapter is also called as NIC.BThe adapter is a semi-autonomous unit.CThe main components of an adapter are bus interface and the link interface.DThe adapter can provide all the link-layer services.8Consider CRC error checking approach, the four bit generator G is 1011, and suppose that the dat

6、a D is , then the value of R is( ).A 010 B 100 C 011 D 1109In the following four descriptions about random access protocol, which one is not correct? ( )A In slotted ALOHA, nodes can transmit at random time.B In pure ALOHA, if a frame experiences a collision, the node will immediately retransmit it

7、with probability p.C The maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.D In CSMA/CD, one node listens to the channel before transmitting.10In the following descriptions about MAC address, which one is not correct? ( )A The MAC address is the address of one nodes adapter.B No two

8、adapters have the same MAC address.C The MAC address doesnt change no matter where the adapter goes.D MAC address has a hierarchical structure.11The ARP protocol can translate ( ) into ( ). ( )A host name, IP address B host name, MAC addressC IP address, MAC address Dbroadcast address, IP address12T

9、he value of Preamble field in Ethernet frame structure is ( )A B C D 13There are four steps in DHCP, the DHCP server can complete ( ).ADHCP server discovery BDHCP server offersCDHCP request DDHCP response14In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the follow

10、ing four times, which one is impossible? ( )A0 bit times B512 bit times C1024 bit times D1028 bit times15The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate( ).Athe maximum length between two adaptersBthe minimum length between two adaptersCthe transmission rate o

11、f the channelDthe transmission rate of the node16The principal components of PPP include but not( ).Aframing Bphysical-control protocol Clink-layer protocol Dnetwork-layer protocol17In the following four options, which service can not be provided by switch? ( )Afiltering Bself-learningCforwarding Do

12、ptimal routing18In the following four services, which one was be required in PPP? ( )Apacket framing Berror detectionCerror correction D multiple types of link19The ability to determine the interfaces to which a frame should be directed, and then directing the frame to those interfaces is( ).A filte

13、ring B forwardingC self-learning D optimal routing20In ( ) transmission(s), the nodes at both ends of a link may transmit packets at the same time.Afull-duplex Bhalf-duplexCsingle-duplexDboth full-duplex and half-duplex21Consider the data D is , if use even parity checking approach, the parity bit i

14、s( ), if use odd parity checking approach, the parity bit is( ). ( ) A0 1B0 0C1 1D1 022In the following four descriptions about parity checks, which one is correct? ( )ASingle-bit parity can detect all errors.BSingle-bit parity can correct one errors.CTwo-dimensional parity not only can detect a sin

15、gle bit error, but also can correct that error.DTwo-dimensional parity not only can detect any combination of two errors, but also can correct them.23MAC address is ( ) bits long.A32 B48 C128 D6424Wireless LAN using protocol ( ).AIEEE 802.3BIEEE 802.4CIEEE 802.5DIEEE 802.1125The following protocols

16、are belonging to multiple access protocols except for ( ).Achannel partitioning protocolsBrouting protocolsCrandom access protocolsDtaking-turns protocols26Which of the following is not belonging to channel partitioning protocols? ( )ACSMABFDMCCDMADTDM27In the following four descriptions about CSMA/

17、CD, which one is not correct? ( )AA node listens to the channel before transmitting.BIf someone else begins talking at the same time, stop talking.CA transmitting node listens to the channel while it is transmitting.DWith CSMA/CD, the collisions can be avoided completely.28( ) provides a mechanism f

18、or nodes to translate IP addresses to link-layer address.AIPBARPCRARPDDNS29A MAC address is a ( )address.Aphysical-layerBapplication-layerClink-layerDnetwork-layer30Which of the following is correct? ( )ANo two adapters have the same MAC address.BMAC broadcast address is FF-FF-FF-FF-FF-FF.CA portabl

19、e computer with an Ethernet card always has the same MAC address, no matter where the computer goes.DAll of the above31In the following four descriptions, which one is not correct? ( )AARP resolves an IP address to a MAC address.BDNS resolves hostnames to IP addresses.CDNS resolves hostnames for hos

20、ts anywhere in the Internet.DARP resolves IP addresses for nodes anywhere in the Internet.32In the LAN, ( )protocol dynamically assign IP addresses to hosts.ADNSBARPCDHCPDIP33DHCP protocol is a four-step process: DHCP request. DHCP ACK. DHCP server discovery. DHCP server offer(s). The correct sequen

21、ce is ( )ABCD34In the Ethernet frame structure, the CRC field is ( )bytes.A2B4C8D3235In the Ethernet frame structure, the Data field carries the ( ).AIP datagramBsegmentCframeDmessage36In the following four descriptions, which one is not correct? ( )AEthernet uses baseband transmission.BAll of the E

22、thernet technologies provide connection-oriented reliable service to the network layer.CThe Ethernet 10Base2 technology uses a thin coaxial cable for the bus.DThe Ethernet 10BaseT technology uses a star topology.37Ethernets multiple access protocol is ( ).ACDMABCSMA/CDCslotted ALOHADtoken-passing pr

23、otocol38In the following four descriptions about CSMA/CD, which one is not correct? ( )AAn adapter may begin to transmit at any time.BAn adapter never transmits a frame when it senses that some other adapter is transmitting.CA transmitting adapter aborts its transmission as soon as it detects that a

24、nother adapter is also transmitting.DAn adapter retransmits when it detects a collision.39Which of the following descriptions about CSMA/CD is correct? ( )ANo slots are used.BIt uses carrier sensing.CIt uses collision detection.DAll of the above.40The Ethernet 10BaseT technology uses( )as its physic

25、al media.Afiber opticsBtwisted-pair copper wireCcoaxial cableDsatellite radio channel41For 10BaseT, the maximum length of the connection between an adapter and the hub is ( )meters.A100B200C500D1042A ( )is a physical-layer device that acts on individual bits rather than on frames.AswitchBhubCrouterD

26、gateway43A hub is a ( )device that acts on individual bits rather than on frames.Aphysical-layerBlink-layerCnetwork-layerDransport-layer44A switch is a( )device that acts on frame.Aphysical-layerBlink-layerCnetwork-layerDtransport-layer45In the following four descriptions, which one is not correct?

27、( )ASwitches can interconnect different LAN technologies.BHubs can interconnect different LAN technologies.CThere is no limit to how large a LAN can be when switches are used to interconnect LAN segments.DThere is restriction on the maximum allowable number of nodes in a collision domain when hubs a

28、re used to interconnect LAN segments.46The ability to determine whether a frame should be forwarded to some interface or should just be dropped is ( ).A filtering B forwardingC self-learning D optimal routing47Which of the following devices is not a plug and play device? ( )AhubBrouterCswitchDrepeat

29、er48Which of the following devices is not cut-through device? ( )AhubBrouterCswitchDrepeater49In the following four descriptions, which one is not correct? ( )ASwitches do not offer any protection against broadcast storms.BRouters provide firewall protection against layer-2 broadcast storms.CBoth sw

30、itches and routers are plug and play devices.DA router is a layer-3 packet switch, a switch is a layer-2 packet switch.50Which device has the same collision domain? ( )AHub BSwitchCRouter DBridge51IEEE802.2 protocol belong to ( )layerAnetwork BMACCLLC Dphysical52IEEE802.11 protocol defines ( )rules.

31、AEthernet Bus Bwireless WANCwireless LANDToken Bus53In data link-layer, which protocol is used to share bandwidth? ( )ASMTPBICMP CARPDCSMA/CD54When two or more nodes on the LAN segments transmit at the same time, there will be a collision and all of the transmitting nodes well enter exponential back

32、-off, that is all of the LAN segments belong to the same( ).Acollision domainBswitchCbridgeDhub55( )allows different nodes to transmit simultaneously and yet have their respective receivers correctly receive a senders encoded data bits.ACDMA BCSMA CCSMA/CD DCSMA/CA56Because there are both network-la

33、yer addresses (for example, Internet IP addresses) and link-layer addresses (that is, LAN addresses), there is a need to translate between them. For the Internet, this is the job of ( ).ARIP BOSPF CARP DIP57PPP defines a special control escape byte, ( ). If the flag sequence, appears anywhere in the

34、 frame, except in the flag field, PPP precedes that instance of the flag pattern with the control escape byte.ABC D58The device ( ) can isolate collision domains for each of the LAN segment.AmodemBswitchChub DNIC59In the following four descriptions about PPP, which one is not correct? ( )APPP is req

35、uired to detect and correct errors.BPPP is not required to deliver frames to the link receiver in the same order in which they were sent by the link sender.CPPP need only operate over links that have a single sender and a single receiver.DPPP is not required to provide flow control.60In the PPP data

36、 frame, the( ) field tells the PPP receivers the upper-layer protocol to which the received encapsulated data belongs.AflagBcontrolCprotocolDchecksum61PPPs link-control protocols (LCP) accomplish ( ).Ainitializing the PPP linkBmaintaining the PPP linkCtaking down the PPP linkDall of the above62The P

37、PP link always begins in the ( ) state and ends in the ( ) state. ( )Aopen, terminatingBopen, deadCdead, deadDdead, terminating63For( ) links that have a single sender at one end of the link and a single receiver at the other end of the link.Apoint-to-pointBbroadcastCmulticastDall of the above64With

38、 ( )transmission, the nodes at both ends of a link may transmit packets at the same time.Ahalf-duplexBfull-duplexCsimplex(单工)Dsynchronous65With ( ) transmission, a node can not both transmit and receive at the same time.Ahalf-duplexBfull-duplexCsimplex(单工)Dsynchronous66Which of the following functio

39、ns cant be implemented in the NIC? ( )Aencapsulation and decapsulationBerror detectionCmultiple access protocolDrouting67Which of the following four descriptions is wrong? ( )AThe bus interface of an adapter is responsible for communication with the adapters parent node.BThe link interface of an ada

40、pter is responsible for implementing the link-layer protocol.CThe bus interface may provide error detection, random access functions.DThe main components of an adapter are the bus interface and the link interface.68For odd parity schemes, which of the following is correct? ( )ABCD69( )divides time i

41、nto time frames and further divides each time frame into N time slots.AFDMBTMDCCDMADCSMA70With CDMA, each node is assigned a different ( )AcodeBtime slotCfrequencyDlink71Which of the following four descriptions about random access protocol is not correct? ( )AA transmission node transmits at the ful

42、l rate of the channelBWhen a collision happens, each node involved in the collision retransmits at once.CBoth slotted ALOHA and CSMA/CD are random access protocols.DWith random access protocol, there may be empty slots.72PPP defines a special control escape byte . If the data is b1bb3b4b5, the value

43、 is( )after byte stuffing.Ab1bb3b4b5Bb1bb3b4b5Cb5b4bb2b1Db5b4bb2b173MAC address is in ( ) of the computer.ARAMBNICChard diskDcache74Which of the following is wrong? ( )AARP table is configured by a system administratorBARP table is built automaticallyCARP table is dynamicDARP table maps IP addresses

44、 to MAC addresses75NIC works in ( )layer.AphysicalBlinkCnetworkDtransport76In LAN, if UTP is used, the common connector is( ).AAUIBBNCCRJ-45DNNI77The modems function(s) is(are) ( ).Atranslates digital signal into analog signalBtranslates analog signal into digital signalCboth translates analog signa

45、l into digital signal and translates digital signal into analog signalDtranslates one kind of digital signal into another digital signal78( )defines Token-Ring protocol.AIEEE 802.3BIEEE 802.4CIEEE 802.5DIEEE 802.279( )defines Token-Bus protocol.AIEEE 802.3BIEEE 802.4CIEEE 802.5DIEEE 802.280( ) defines CSMA/CD protocol.AIEEE 802.3BIEEE 802.4CIEEE 802.5DIEEE 802.281The computer network that concentrated in a geogra