Interactive end-of-chapter exercises


TCP sequence and ACK numbers with segment loss

Consider the figure below in which a TCP sender and receiver communicate over a connection in which the sender->receiver segments may be lost. The TCP sender sends an initial window of 5 segments. Suppose the initial value of the sender->receiver sequence number is 201 and the first 5 segments each contain 179 bytes. The delay between the sender and receiver is 7 time units, and so the first segment arrives at the receiver at t=8. As shown in the figure below, 2 of the 5 segment(s) are lost between the segment and receiver.





Question List


1. Give the sequence numbers associated with each of the 5 segments sent by the sender. Format your answer as: a,b,c,...

2. Give the ACK numbers the receiver sends in response to each of the segments. If a segment never arrives use 'x' to denote it, and format your answer as: a,b,c,...




Solution


1. The sender's sequence numbers are: 201,380,559,738,917

2. The receiver's ACKs are: 380,559,x,x,559



That's incorrect

That's correct

The answer was: 201,380,559,738,917

Question 1 of 2

The answer was: 380,559,x,x,559

Question 2 of 2

Try Another Problem

We gratefully acknowledge the programming and problem design work of John Broderick (UMass '21), which has really helped to substantially improve this site.

Copyright © 2010-2022 J.F. Kurose, K.W. Ross
Comments welcome and appreciated: kurose@cs.umass.edu