计算机网络实验3TCP实验.doc

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电脑网络实验报告三
TCP实验
1. What is the IP address and TCP port number used by the client computer (source)
that is tra
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7. Consider the TCP segment containing the HTTP POST as the first segment in the
TCP connection. What are the sequence numbers of the first six segments in theTCP connection (including the segment containing the HTTP POST)?At what time was each segment sent? When was the ACK for each segment received?Given the difference between when each TCP segment was sent, and when itsacknowledgement was received, what is the RTT value for each of the sixsegments? What is the EstimatedRTT value (see page 249 in text) after thereceipt of each ACK? Assume that the value of the EstimatedRTT is equal tothe measured RTT for the first segment, and then is computed using theEstimatedRTT equation on page 249 for all subsequent : Wireshark has a nice feature that allows you to plot the RTT foreach of the TCP segments sent. Select a TCP segment in the “listing ofcaptured packets” window that is being sent from the client to server. Then select: Statistics->TCP Stream Graph->Round Trip Time Graph.
Segment 1
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Segment 2
Segment 3
Segment 4
Segment 5
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Segment 6
答：,5,7,8,10,11. 对应的ACK分别为 ,9,12,14,15,16.
前6个报文段截图如下：
报文段的序列号为每个报文段的首字节加1，所以序列号为：
Segment 1 sequence number:1
Segment 2 sequence number:566
Segment 3 sequence number:2026
Segment 4 sequence number:3486
Segment 5 sequence number:4946
Segment 6 sequence number:6406
报文段的发送时间和相应ACK 的到达时间如下表：:
Send time
ACK received time
RTT seconds
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Segment 1
Segment 2
Segment 3
Segment 4
Segment 5
Segment 6
EstimatedRTT=* EstimatedRTT+*SampleRTT
接受到报文段1之后的EstimatedRTT为：
EstimatedRTT=RTT for segment 1= second
接受到报文段2之后的EstimatedRTT为：
EstimatedRTT=*+*= sencond
接受到报文段3之后的EstimatedRTT为：
EstimatedRTT=*