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TCP Lab question 12?


Hey guys, trying to do question 12 here, but I'm a bit stumped.

12 . What is the throughput (bytes transferred per unit time) for the TCP connection? Explain how you calculated this value.

The Computer Networking book states that the increase of w happens when a loss event occurs (which doesn't in the provided TCP trace, so that can be ignored (I think?)) Is the final formula:

w/RTT ?

If it is, then how do I find what w and RTT are. Are these the differences between the first TCP and last ACK?

asked 01 Mar '14, 18:35

rainman's gravatar image

accept rate: 0%

What Lab are you referring to? What is the "Computing Networking book"?

(02 Mar '14, 01:44) Jasper ♦♦

One Answer:


Some hints and some questions....

Hint #1: RTT calculation

If you draw a picture of the TCP 3-way handshake (client --> router --> router --> server), what could the RTT (round trip time) be, if you look at the SYN and SYN-ACK frames? How can you use that knowledge to calculate the RTT in a capture file, if the trace was taken on (or near) the client? What changes if you've taken the trace on (or near) the server?

Question(s) #1: w?

How is w defined in the book? In some papers I've read, w is the congestion window. Is it the same in the book? If so, did you find a definition of the congestion window in the book or with the help of Mr. search engine? If no, please search it. Then: How would you describe it in your own words?


answered 02 Mar '14, 07:37

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
accept rate: 15%

edited 02 Mar '14, 07:37