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 [] C.Network [] 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.What’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

15. Large IP datagram divided (“fragmented”) within network,it will be reassembled:B

[] A. only at last router

[] B. only at final destination [] C. only at next router [] D. maybe at next router

16.Which is not a common Intra-AS routing protocols:D

[] A.RIP: Routing Information Protocol [] B.OSPF: Open Shortest Path First

[] C.IGRP: Interior Gateway Routing Protocol [] D.ICMP: Interior Control Message Protocol

17.Which is not a MAC Random Access protocol in Ethernet: D

[] A.SCMA

[] B.SCMA/CA [] C.SCMA/CD

[] D.Slotted SCMA

18.In DHCP client-server scenario, which message has DHCP-options field:D

[] A. host broadcasts “DHCP discover”

[] B. DHCP server responds with “DHCP offer” [] C. host requests IP address: “DHCP request” [] D. DHCP server sends address: “DHCP ack”

19.How to determine MAC address of host B, If knowing host B’s IP address?A

[] A.ARP [] B.RARP [] C.RAP [] D.RIP

20. Which device can break subnet into LAN segments: C

[] A.IP mask

[] B.NAT [] C.Router [] D.Switch

II.

Choose the multiple correct answer from following choose. (2*10=20)

[All correct checked:2; Part correct checked:1; No checked:0; Full checked:0] 1.Which is the part of network structure: ABD

[] A.network edge [] B.network core [] C.network user

[] D.access networks

2.How to connect end systems to edge router? BCD

[] A.Microsoft access networks [] B.Residential access networks

[] C.Institutional access networks [] D.Mobile access networks

3.What kind of transport service does an application need? ABC

[] A.Data loss

[] B.Timing [] C.Bandwidth [] D.Security

4.Electronic Mail three phases of transfer is: ABD

[] A.handshaking (greeting) [] B.transfer of messages

[] C.opens the 2nd TCP connection [] D.close

5.In TCP Connection Management, initialize TCP variables include： AB

[] A.sequence # [] B.buffers [] C.Sender MTU [] D.RcvWindow

6.How does sender perceive congestion? AB [] A.timeout

[] B.3 duplicate ACKs [] C.3 duplicate data [] D.slow start

7.TCP Congestion Control use three mechanisms: ABC [] A.additive increase and multiplicative decrease

[] B.slow start

[] C.Conservative after timeout events

[] D.additive decrease and multiplicative increase

8.What are the Key Network-Layer Functions: ABC

[] A.forwarding [] B.routing

[] C.connection setup [] D.flow control

9.Link Layer Services include: ABD [] A.Reliable delivery between adjacent nodes [] B.Flow Control between adjacent nodes [] C.Connection Manage

[] D.Error Detection and Correction

10.MAC Protocol’s taxonomy, three broad classes is: ABC [] A.Channel Partitioning

[] B.Random Access [] C.Taking turns [] D.Peer-to-peer

III.

Fill the blank from options. (1.5*16=24)

1).The network protocols define format , order of message sent and received among network entities, and action taken on message transmission, receipt.

(options: delay / format / policy / order / request / replay / actions taken / price / interface )