计算机网络英文题库(附答案)chapter3

A Receive window B Congestion window C Sliding window D buffer

80. How does TCP sender perceive congestion A Timeout

B 3 duplicate ACK-s C Both A and B D None of above

81. Transport protocols run in ____. A Servers B Clients C Routers D End systems

82. 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

83. Which service does UDP not provide A multiplexing B de-multiplexing C error-detection D error-correction

84. There are three major events related to data transmission and retransmission in the TCP sender, which one is not in it A data received from application above

B de-multiplexing segment

C timer timeout D ACK receipt

85. Which of the following applications normally uses UDP services A SMTP

B Streaming multimedia C FTP D HTTP

86. Which of the following about TCP connection is not correct 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 87. The SYN segment is used for____. A TCP connection setup B TCP flow control C TCP congestion control D Closing a TCP connection

88. Which service helps prevent the internet from entering a state of gridlock

A reliable data transfer B flow control

C congestion control D handshaking procedure

89. The Internet’s _____is responsible for moving packets from one host to another.

A application layer B transport layer

C network layer D link layer

90.In the following applications, which one is a bandwidth-sensitive

application

A E-mail

B web application C real-time audio D file transfer

91. In the following applications, which one uses UDP A E-mail

B web application C file transfer D DNS

92. In the following four descriptions, which one is correct

A If one host’s transport layer uses TCP, then its network layer must use virtual-circuit network.

B Datagram network provides connection service

C The transport-layer connection service is implemented in the router D The network-layer connection service is implemented in the router as well as in the end system.

93. ____ is a speeding-matching service---matching the rate which the sender is sending against the rate at which the receiving application is reading.

A congestion control B flow control

C sliding-window control D variable control

94. In the following four descriptions about Rcv-Window, which one is correct

A The size of the TCP RcvWindow never changes throughout the duration of the connection

B The size of the TCP RcvWindow will change with the size of the TCP RcvBuffer

C The size of the TCP RcvWindow must be less than or equal to the size of the TCP RcvBuffer

D Suppose host A sends a file to host B over a TCP connection, the number of unacknowledged bytes that A sends cannot exceed the size of the size of the RcvWindow.

95. There are 6 flag fields. Which one is to indicate that the receiver should pass the data to the upper layer immediately A PSH B URG C ACK D RST

96. Suppose the TCP receiver receives the segment that partially or completely fills in gap in received data, it will ____. A immediately send ACK B immediately send duplicate ACK

C wait some time for arrival of another in-order segment D send single cumulative

97. _____ imposes constrain on the rate at which a TCP sender can send traffic into the network.