计算机网络英文题库(附答案)chapter3

(A)Timeout

(B)Triple duplicate ACK

e) After the 19th transmission round, segment loss detected by ____.

(A)Timeout

(B)Triple duplicate ACK

f) During ____ transmission round, the 18th segment is sent.

the TCP reliable data transfer in the given graph. If in Segment 1’s Sequence number =10,data=“AC”, please fill in the following blanks. a) In Segment 2, ACK number=____;

b) In Segment 3, Sequence number =____; data=“0123456789”

c) If there are some bits corrupted in segment 3 when it arrives Host B, then the ACK number in Segment 5 is ____; and the ACK number in Segment 6 is ____.

1 2 3 4 5 6 7

4. The client A wants to request a Web page from Server B. Suppose the URL of the page is and also it wants to receive French version of object. The time-sequence diagram is shown below, please fill in the blanks.

1 2 3 4 5

Packet① to Packet③ are TCP connection’s segment, then: Packet ①: SYN flag bit= a ACK flag bit= b Sequence number= 92 Packet ②: SYN flag bit=1 ACK flag bit= c Sequence number=100 Packet ③: SYN flag bit= d ACK flag bit=1 Sequence number= e

5. Consider sending an object of size O=100 Kbytes from server to client. Let S=536 bytes and RTT=100msec. Suppose the transport protocol uses static windows with window size W.

(1) For a transmission rate of 25 kbps, determine the minimum possible latency. Determine the minimum window size that achieves this latency. (2) Repeat (1) for 100 kbps.

6. Consider the following plot of TCP congestion window size as a function of time. Please fill in the blanks as below.

a) The initial value of Threshold at the first transmission round is____.

b) The value of Threshold at the 11th transmission round is_____. c) The value of Threshold at the 21st transmission round is_____.

Congestion window size 16 12 8 4 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 Transmission round

d) After the 9th transmission round, _____ occurs. e) After the 19th transmission round, ____ are detected.