计算机网络英文题库.docx

Chapter 3 Transport Layer 1. A transport-layer protocol provides for logical communication between ____. Application processes Hosts Routers End systems Transport-layer protocols run in ____. A Servers B Clients C Routers D End systems 3. In transport layer, the send side breaks application messages into ____, passes to network layer. Frames Segments Data-grams bit streams Services provided by transport layer include ____. A HTTP and FTP B TCP and IP C TCP and UDP D SMTP Which of the following services is not provided by TCP? A Delay guarantees and bandwidth guarantees B Reliable data transfers and flow controls C Congestion controls D In-order data transfers 6. These two minimal transport-layer services____ and ____are the only two services that UDP provides! process-to-process data delivery, error checking congestion control, reliable data transfer flow control, congestion control In-order data transfer, error checking Port number ’s scop e is ____ to ____. A 0, 1023 B 0, 65535 C 0, 127 D 0,255 The port numbers ranging from ____to ____ are called well-known port number and are restricted. A 0, 1023 B 0, 65535 0, 127 0,255 UDP socket identified by two components, they are ____. A source IP addresses and source port numbers B source IP addresses and destination IP addresses C destination IP address and destination port numbers destination port numbers and source port numbers 10. TCP socket identified by a (an) ____. A 1-tuple B 2-tuple C 3-tuple D 4-tuple 11. Which of the following applications normally uses UDP services? A SMTP B Streaming multimedia C FTP D HTTP 12. Reliable data transfer protocol over a perfectly reliable channel is____. A B C D 13. Reliable data transfer protocol over a channel with bit errors and packet losses is ____. A B C D 14. Which of the following about reliable data transfer over a channel with bit errors is not correct? A : assuming ACK and NAK will not be corrupted B : assuming ACK and NAK can be corrupted C : only use ACK-s D : u