川大软院计网选择题答案Chapter3含答案

CHAPTER 3: TRANSPORT LAYER 1.A transport-layer protocol provides for logical communication between ___C_. A.Routers B.Hosts C.Application processes D.End systems 2.Transport-layer protocols run in __D__. A.Servers B.Clients C.Routers D.End systems 3.In transport layer, the send side breaks application messages into ___B_, passes to network layer. A.Frames B.Segments C.Data-grams D.bit streams 4.The receive side of transport layer reassembles segments into messages, passes to __A__layer. A.Application B.Networking C.Physical D.MAC 5.Services provided by transport layer include __C__. A.HTTP and FTP B.TCP and IP C.TCP and UDP D.SMTP 6.Which of the following services is not provided by TCP?D A.In-order data transfers B.Reliable data transfers and flow controls C.Congestion controls D.Delay guarantees and bandwidth guarantees 7.These two minimal transport-layer services----___A_ and ____----are the only two services that UDP provides A.process-to-process data delivery, error checking B.congestion control, reliable data transfer C.flow control, congestion control D.In-order data transfer, error checking 8.UDP offers which of the following benefits relative to TCP?C A.UDP guarantees that Individual packets of a transmission will arrive “in order” B.UDP supports a self-regulating “throttle” feature that prevents network saturation C.UDP consumes fewer computer resources by not maintaining connection state D.None of the above 9.Which of the following applications normally uses UDP services?B A.SMTP B.Streaming multimedia C.FTP D.HTTP 10. The job of gathering data chunks, encapsulating each data chunk with header ination to create segments and passing the segments to the network is called __A__. A.multiplexing B.de-multiplexing C.forwarding D.routing 11. This job of delivering the data in a transport-layer segment to the correct socket is called _B___. A.multiplexing B.de-multiplexing C.forwarding D.routing 12. Port number’s scope is ___B_ to ____. A.0, 1023 B.0, 65535 C.0, 127 D.0,255 13. The port numbers ranging from __C__to ____ are called well-known port number and are restricted. A.0, 127 B.0, 65535 C.0, 1023 D.0,255 14. The UDP header has only four fields, they are__A__. A.Source port number, destination port number, length and checksum B.Source port number, destination port number, source IP and destination IP C.source IP, destination IP, source MAC address and destination MAC address D.source IP, destination IP, sequence number and ACK sequence number 15. The field of Length in UDP segment specifies the length of ___B_. A.the UDP segment, not including the header B.the UDP segment, including the header C.the UDP segment’s header D.the Length field 16. Which of the following about TCP connection is not correct?A A.It is a broadcast connection B.It is a point-to-point connection C.It is a pipelined connection D.It is a full duplex connection 17. In the following four descriptions about MSS and MTU, which one is not correct?C A.The MSS is typical