1、.Chapter 2 Application Layer1. In the following four descriptions, which one is correct? A In C/S architecture, clients communicate with each other directly.B In C/S architecture, client has a fixed well-known address.C In P2P architecture, peers communicate with each other directly.D In P2P archite
2、cture, peer has a fixed well-known address.2. In the context of a communication session between a pair of process, the process that initiates the communication is labeled as the , the process that waits to be contacted to begin the session is labeled as the .A client process, server process B sendin
3、g process, receiving processC input process, output process D communicating process, connecting process3. A socket is the interface between within a host. A the network layer and the link layerB the link layer and the physical layerC the application layer and the transport layerD the transport layer
4、 and the network layer4. In the following applications, which one is a loss-tolerant application? A E-mail B file transfer C instant messaging D real-time audio5. In the following applications, which one is a bandwidth-sensitive application? A E-mail B web application C real-time audio D file transf
5、er6. The service of TCP cant guarantee .A delivery of all data without error B delivery of all data in the proper orderC the rate of delivery D congestion control7. In the following applications, which one uses UDP? A E-mail B web application C file transfer D DNS8. In the following descriptions abo
6、ut HTTP, which one is not correct? A HTTP uses non-persistent connections in its default mode.B HTTP uses TCP as its underlying transport protocol.C HTTP is a stateless protocol.D HTTP is client-server architecture.9. Suppose a web page consists of a base HTML file, 5 JEPG images and a java applet,
7、and also suppose HTTP uses persistent connection without pipelining, the total response time is .A 2RTT B 8RTT C 12 RTT D 14RTT10. In HTTP response message, if the requested HTTP protocol version is not supported, the status code is .A 200 B 301 C 400 D 50515CACDC610CDABD11. The port number of web a
8、pplication is .A 25 B 20 C 80 D 5312. A network entity that satisfies HTTP requests on the behalf of an origin web server is .A server farm B server stack C proxy server D edge server13. In the following descriptions about persistent connection, which one is not correct? A The server leaves the TCP
9、connection open after sending a response.B Each TCP connection is closed after the server sending one object.C There are two versions of persistent connection: without pipelining and with pipelining.D The default mode of HTTP uses persistent connection with pipelining.14. FTP uses two parallel TCP c
10、onnections to transfer a file, there are .A control connection and data connectionB receiving connection and sending connectionC client connection and sever connectionD program connection and process connection15. In the following descriptions about FTP, which one is correct?A FTP is p2p architectur
11、e. B FTP sends its control information out-of-band.C FTP uses persistent connection. D FTP is a stateless protocol.16.InthecommandsofFTP,whichonedoesnothaveparameter?AUSERBPASSCLISTDSTOR17. The Internet mail system has three components which they are .A user agent, SMTP, POP3 B SMTP, POP3, IMAPC use
12、r agent, SMTP, IMAP D user agent, SMTP, mail server18. If the status code in HTTP response message is 404, it means .A Request succeeded. B The requested document doesnt exit on this server.C This is a generic error code indicating that the request could not be understood by the server.D Requested o
13、bject has been permanently mover.19. Comparison HTTP with SMTP, the correct is .A HTTP is a push protocol, and SMTP is a pull protocol.B In the default mode, both of them use persistent connection.C HTTP places all of the messages objects into one message, and SMTP sends every object one by one.D HT
14、TP requires each message to be in 7-bit ASCII format, and SMTP doesnt impose this restriction.20. The headers in the MIME message must include except .A From B Content-type C Content-transfer-encoding D MIME version1115CCBAB1620DDBBD21. In the following protocol, which one is stateless? A POP3 B SMT
15、P C FTP D IMAP22. DNS means .A Data Name System B Data National SystemC Domain Name System D Domain National System23. There are three classes of DNS server except .A Root DNS server B Local DNS serverC TLD server D Authoritative DNS server24. DNS provides some services except .A Host aliasing B Mai
16、l server aliasingC Load distribution D A single point of failure25.TherearethreearchitecturesforlocatingcontentinP2Pfilesharing,KaZaAuses.ACentralizedDirectory（Napster）BQueryFlooding(Gnutella)CExploitingHeterogeneity(p141)DIncentivePriorities26.TherearethreearchitecturesforlocatingcontentinP2Pfilesh
17、aring,Napsteruses.ACentralizedDirectory(p137)BQueryFloodingCExploitingHeterogeneityDIncentivePriorities27.ThefollowingarchitecturesinP2Pfilesharing,whichisanoverlaynetwork?ACentralizedDirectoryBQueryFlooding(p139)CExploitingHeterogeneityDIncentivePriorities28. The time it takes for a small packet to
18、 travel from client to server and then back to the client is .A round-travel time B next-hop timeC round-trip time D prefix-matching time29. Suppose A ( with a Web-based e-mail account ) sends a message to B ( who accesses his mail server using POP3), which application-layer protocol is not used? A
19、HTTP B SMTP C POP3 D IMAP30. In the four following options, which protocol is included in Mail Access Protocol? A SMTP B DHCP C IMAP D FTP31. In FTP commands, is used to send user password to the server.A User B Pass C Retr D Stor32. The function of the additional header field in MIME Content-Type i
20、s .A to convert the message body to its origin non-ASCII formB to determine what actions it should take on message bodyC to send an E-mail to the receiving user agentD to indicate what type the message is33. In the four following options, which application is organized as hybrid of C/S and P2P archi
21、tecture? A E-mail B OICQ C File transfer D Web application34.Inthefourfollowingoptions,whichisnotacentralizedDNSdesignsproblem?AasinglepointoffailureBtrafficvolumeCdistantcentralizeddatabaseDslow(maintenance)35. In the following options, from the application developers perspective, which is not corr
22、ect? A the network architecture is fixedB the network architecture provides a specific set of services to applicationsC the application architecture is designed by the physical devicesD the application architecture dictates how the application is organized over the various end systems36. There are t
23、hree predominant architectures used in modern network applications, which one is not included? A the client-server architecture B the P2P architectureC a hybrid of the client-server and P2P architectureD a hybrid of the client-server and browser-server architecture37. In the following options about
24、C/S architecture, which is not correct? A In C/S architecture, there is an always-on host, called the server.B In C/S architecture, there is an always-on host, called the client.C The server has a fixed, well-known address, called IP address.D Clients do not directly communicate with each other.38.a
25、reoftenusedtocreateapowerfulvirtualserverinC/Sarchitecture.APeersBServerfarmCserverstackDlocalserver39. A process sends messages into, and receives messages from, the network through its .A socket B program C client D peer40. Which one is not defined by an application-layer protocol? A the types of
26、messages exchangedB the syntax of various message typesC the semantics of the fieldsD rules for determining when and how to translate the socket41. HTTP can use two types of connections, which are .A persistent and non-persistent connectionB connection with pipelining and without pipeliningC TCP and
27、 UDPD parallel and serial connection42. takes for a small packet to travel from client to server and then back to the client.A RDT B threshold C RTT D overhead43. The default mode of HTTP uses .A non-persistent connection with pipeliningB non-persistent connection without pipeliningC persistent conn
28、ection with pipeliningD persistent connection without pipelining44. In HTTP request messages, the request line has three fields, there are .A the method field, the URL field and the HTTP version fieldB the method, the connection and URL fieldC the user-agent, the method and HTTP version fieldD the u
29、ser-agent, the URL and the HTTP version field45. In the header lines of HTTP request message, if the field of Connection is close, it specifies .A the host on which object residesB what type of the user agentC that the browser wants the server to close the connection after sending the requested obje
30、ctD which language can the browser receive46. In HTTP response message, if the status code is 404, it means .A request succeeded and the information is returned in the responseB requested object has been permanently movedC the requested HTTP protocol version is not supported by the serverD the reque
31、sted document does not exist on this server47. is a network entity that satisfies HTTP requests on the behalf of an origin Web server.A proxy server B local server C DNS server D Web server48. In the following four options about web cache, which one is not correct? A A web cache is both a server and
32、 a client at the same time.B A web cache is purchased and installed by an ISP.C A web cache can raise the response time for a client request.D A web cache can reduce traffic on an institutions access link to the Internet.49. The request message in the conditional GET must include the header line.A L
33、ast-Modified B Last-ReferencedC If-Modified-Since D If Referenced-Since50. FTP uses two parallel connections to transfer a file, they are .A TCP and UDP connectionB connection with pipelining and without pipeliningC control an data connectionD client-server and browser-server connection51. In FTP co
34、mmands, which one is used to ask the server to send back a list of all files in the current remote directory? A USER B PASS C LIST D RETR52. In the Internet mail system, allow users to read, reply to, forward, save and compose message.A User agents B mail servers C SMTP D TCP53. The two key MIME hea
35、ders for supporting multimedia are .A Content-Type and MIME-VersionB Content-Type and Content-Transfer-EncodingC Content-Transfer-Encoding and MIME-VersionD MIME-Version and MIME-Type54. For Internet mail, the mail access protocol is used to .A transfer mail from the recipients mail server to the re
36、cipients user agentB transfer mail from the senders mail server to the recipients mail serverC translate the mail from the senders mail serverD translate the mail into the recipients mail server55. POP3 progresses through three phases, which they are .A authorization, translation and transactionB au
37、thorization, translation and updateC authorization, transaction and updateD translation, transaction and update56. In the following four services, which one can not provide by DNS? A Host aliasing B Mail server aliasingC translate hostname to IP addressesD translate MAC addresses to IP addresses57.
38、There are three classes of DNS servers, there are .A root DNS server, top-level domain DNS server and local DNS serverB root DNS server, top-level domain DNS server and authoritative DNS serverC root DNS server, local DNS server and authoritative DNS serverD root DNS server, local DNS server and top
39、-level domain DNS server58. In the following four options about POP3, which one is not correct? A The user agent employed only three commands: List, Retr and QuitB The server does not carry state information across POP3 sessionsC The port number is 110D The POP3 protocol does not provide any means f
40、or a user to create remote folders and assign messages to folders.59.AresourcerecordinDNSdistributeddatabaseisafour-tuple,whichfieldcanbeignored?(p132)ANameBValueCTypeDTTL60.InthefollowingfouroptionsaboutDNSresourcerecord,whichoneiscorrect?AThemeaningofNameandValuedependonType.BThemeaningofValueandT
41、ypedependonName.CIfType=A,thenNameisadomainandValueistheIPaddressforthehostname.DIfType=MX,thenNameisdomainandValueistheIPaddressforthehostname.61.InthefollowingfouroptionsaboutDNSmessages,whichoneisnotcorrect?AThereareonlytwokindsofDNSmessage.(p133)BBothqueryandreplymessagehavethesameformat.CThehea
42、dersectioninDNSmessagehas12bytes.DTheauthoritysectioncontainstheresourcerecordsforthesamethatwasoriginallyqueried.62.InDNSmessage,containsinformationaboutthequerythatisbeingmade.(p133)AauthoritysectionBquestionsectionCanswersectionDadditionalsection63.TherearethreetechniquesareemployedinmostanyP2Pfile-sharingsystems,whichoneisnotinclude?（p144）ARequestqueuingBincentiveprioritiesCparalleldownloadingDResponsequeuing64. In the following four opt
