宁波大学计算机网络期末试卷(英文)

I.Choose the single correct answer from following choose. (1.5*20=30)

[Correct checked:1.5; Other wise:0]

1.Which physical media has high-speed operation and low error rate:A

[] A.Fiber optic cable

[] B.Coaxial cable

[] C.Twisted pair

[] D.Radio

2.If no free buffers in router, the arriving packets will be: B

[] A.dropped

[] B.queued

[] C.returned

[] D.marked

3.Which can provides delay measurement from source to router along end-end Internet path towards destination: A

[] A.Ping

[] B.Traceroute

[] C.Ipconfig

[] D.Nslookup

4.In TCP/IP, which layer can make routing of datagrams from source to destination: C

[] A.Applicaion

[] B.Transport

[] work

[] D.Data Link

5.Web page consists of ( ) which includes several referenced objects：A

[] A.referenced HTML-file

[] B.host HTML-file

[] C.path HTML-file

[] D.base HTML-file

6.What is the default persistent model in HTTP/1.1:C

[] A.Nonpersistent HTTP

[] B.Persistent without pipelining

[] C.Persistent with pipelining

[] D.Nonpersistent with pipelining

7.Web server maintains no information about past client requests, so HTTP is:B

[] A.stateful

[] B.stateless

[] C.satisfied

[] D.unsatisfied

8.FTP client browses remote directory by sending commands over: D

[] A.connection-less

[] B.free connection

[] C.data connection

[] D.control connection

9.Which can satisfy client request without involving origin server A

[] A.Web caches

[] B.Write caches

[] C.TCP buffer

[] D.Router buffer

10.UDP socket identified by:B

[] A.two-tuple (source IP address, source port number)

[] B.two-tuple (dest IP address, dest port number)

[] C.two-tuple (source IP address, dest port number)

[] D.two-tuple (dest IP address, source port number)

11.In GBN,when receiver receive a out-of-order packet,then discard and re-ACK the packet with:

[] A. highest in-order sequence # A

[] B. lowest in-order sequence #

[] C. highest in-order port #

[] D. lowest in-order port #

12.In RDT Approachs, which is designed for performance: B

[] A. checksum

[] B. pipeline

[] C. sequence #

[] D. ACK or NAK

13.Queued datagram at front of router’s queue prevents others in queue from moving forward is:A

[] A.Head-of-the-Line (HOL) blocking

[] B.Hops-of-the-Line (HOL) blocking

[] C.Head-of-the-List (HOL) blocking

[] D.Hops-of-the-List (HOL) blocking

14.Wha t’s a network ? From IP address perspective they can physically reach each other without intervening router and the device interfaces with: C

[] A. same IP address

[] B. same TCP port #

[] C. same network part of IP address

[] D. same host part of IP address