计算机网络英文题库附答案chapter5.docx

1、计算机网络英文题库附答案chapter5Chapter 5 The Link Layer and Local Area Network1A ( ) protocol is used to move a datagram over an individual link.A application-layer B transport-layerC network-layer D link-layer2The units of data exchanged by a link-layer protocol are called ( ).A datagrams B framesC segments D

2、 messages3Which of the following protocols is not a link-layer protocol? ( )A Ethernet B PPPC HDLC D IP4In the following four descriptions, which one is not correct? ( )A link-layer protocol has the node-to-node job of moving network-layer datagrams over a single link in the path.B The services prov

3、ided by the link-layer protocols may be different.C A datagram must be handled by the same link-layer protocols on the different links in the path.D The actions taken by a link-layer protocol when sending and receiving frames include error detection, flow control and random access.5Which of the foll

4、owing services can not offered by a link-layer protocol? ( )A congestion control B Link Access C Error control D Framing6( ) protocol serves to coordinate the frame transmissions of the many nodes when multiple nodes share a single broadcast link.A ARP B MAC C ICMP D DNS7In the following four descri

5、ptions about the adapter, which one is not correct? ( )A The adapter is also called as NIC.B The adapter is a semi-autonomous unit.C The main components of an adapter are bus interface and the link interface.D The adapter can provide all the link-layer services.8Consider CRC error checking approach,

6、 the four bit generator G is 1011, and suppose that the data D is 10101010, 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 fram

7、e experiences a collision, the node will immediately retransmit it 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?

8、 ( )A The MAC address is the address of one nodes adapter.B No two 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

9、 addressC IP address, MAC address D broadcast address, IP address12The value of Preamble field in Ethernet frame structure is ( )A 10101010 1010101010101010 11111111B 10101011 1010101110101011 10101011C 10101010 1010101010101010 10101011D 10101010 1010101010101010 1010101013There are four steps in D

10、HCP, the DHCP server can complete ( ).A DHCP server discovery B DHCP server offersC DHCP request D DHCP response14In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the following four times, which one is impossible? ( )A 0 bit times B 512 bit times C 1024 bit times D

11、 1028 bit times15The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate( ).A the maximum length between two adaptersB the minimum length between two adaptersC the transmission rate of the channelD the transmission rate of the node16The principal components of PPP inc

12、lude but not( ).A framing B physical-control protocol C link-layer protocol D network-layer protocol17In the following four options, which service can not be provided by switch? ( )A filtering B self-learningC forwarding D optimal routing18In the following four services, which one was be required in

13、 PPP? ( )A packet framing B error detectionC error 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 filtering B forwardingC self-learning D optimal routing20In ( ) transmission(s

14、), the nodes at both ends of a link may transmit packets at the same time.A full-duplex B half-duplexC single-duplex D both full-duplex and half-duplex21Consider the data D is 01110010001, if use even parity checking approach, the parity bit is( ), if use odd parity checking approach, the parity bit

15、 is( ). ( ) A 0 1 B 0 0C 1 1 D 1 022In the following four descriptions about parity checks, which one is correct? ( )A Single-bit parity can detect all errors.B Single-bit parity can correct one errors.C Two-dimensional parity not only can detect a single bit error, but also can correct that error.D

16、 Two-dimensional parity not only can detect any combination of two errors, but also can correct them.23MAC address is ( ) bits long.A 32 B 48 C 128 D 6424Wireless LAN using protocol ( ).A IEEE 802.3 B IEEE 802.4C IEEE 802.5 D IEEE 802.1125The following protocols are belonging to multiple access prot

17、ocols except for ( ).A channel partitioning protocols B routing protocolsC random access protocols D taking-turns protocols26Which of the following is not belonging to channel partitioning protocols? ( )A CSMA B FDM C CDMA D TDM27In the following four descriptions about CSMA/CD, which one is not cor

18、rect? ( )A A node listens to the channel before transmitting.B If someone else begins talking at the same time, stop talking.C A transmitting node listens to the channel while it is transmitting.D With CSMA/CD, the collisions can be avoided completely.28( ) provides a mechanism for nodes to translat

19、e IP addresses to link-layer address.A IP B ARP C RARP D DNS29A MAC address is a ( )address.A physical-layer B application-layerC link-layer D network-layer30Which of the following is correct? ( )A No two adapters have the same MAC address.B MAC broadcast address is FF-FF-FF-FF-FF-FF.C A portable co

20、mputer with an Ethernet card always has the same MAC address, no matter where the computer goes.D All of the above31In the following four descriptions, which one is not correct? ( )A ARP resolves an IP address to a MAC address.B DNS resolves hostnames to IP addresses.C DNS resolves hostnames for hos

21、ts anywhere in the Internet.D ARP resolves IP addresses for nodes anywhere in the Internet.32In the LAN, ( )protocol dynamically assign IP addresses to hosts.A DNS B ARP C DHCP D IP33DHCP protocol is a four-step process: DHCP request. DHCP ACK. DHCP server discovery. DHCP server offer(s). The correc

22、t sequence is ( )A B C D 34In the Ethernet frame structure, the CRC field is ( )bytes.A 2 B 4 C 8 D 3235In the Ethernet frame structure, the Data field carries the ( ).A IP datagram B segment C frame D message36In the following four descriptions, which one is not correct? ( )A Ethernet uses baseband

23、 transmission.B All of the Ethernet technologies provide connection-oriented reliable service to the network layer.C The Ethernet 10Base2 technology uses a thin coaxial cable for the bus.D The Ethernet 10BaseT technology uses a star topology.37Ethernets multiple access protocol is ( ).A CDMA B CSMA/

24、CD C slotted ALOHA D token-passing protocol38In the following four descriptions about CSMA/CD, which one is not correct? ( )A An adapter may begin to transmit at any time.B An adapter never transmits a frame when it senses that some other adapter is transmitting.C A transmitting adapter aborts its t

25、ransmission as soon as it detects that another adapter is also transmitting.D An adapter retransmits when it detects a collision.39Which of the following descriptions about CSMA/CD is correct? ( )A No slots are used.B It uses carrier sensing.C It uses collision detection.D All of the above.40The Eth

26、ernet 10BaseT technology uses( )as its physical media.A fiber optics B twisted-pair copper wireC coaxial cable D satellite radio channel41For 10BaseT, the maximum length of the connection between an adapter and the hub is ( )meters.A 100 B 200 C 500 D 1042A ( )is a physical-layer device that acts on

27、 individual bits rather than on frames.A switch B hub C router D gateway43A hub is a ( )device that acts on individual bits rather than on frames.A physical-layer B link-layerC network-layer D ransport-layer44A switch is a( )device that acts on frame.A physical-layer B link-layerC network-layer D tr

28、ansport-layer45In the following four descriptions, which one is not correct? ( )A Switches can interconnect different LAN technologies.B Hubs can interconnect different LAN technologies.C There is no limit to how large a LAN can be when switches are used to interconnect LAN segments.D There is restr

29、iction on the maximum allowable number of nodes in a collision domain when hubs are 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

30、the following devices is not a plug and play device? ( )A hub B router C switch D repeater48Which of the following devices is not cut-through device? ( )A hub B router C switch D repeater49In the following four descriptions, which one is not correct? ( )A Switches do not offer any protection against broadcast storms.B Routers provide firewall protection against layer-2 broadcast storms.C Both switches and routers are plug and play devices.D A router is a layer-3 packet switch, a switch is a layer-2 packet switch.50Which device has the same collision domain? ( )A Hub B S