Network Analysis Using Wireshark 2 Cookbook - Second Edition

Case 5 - retransmission due to delayed variations

TCP is a protocol that is quite tolerant to delays as long as the delay does not vary. When you have variations in a delay, you can expect retransmissions. The way to find out whether this is the problem is as follows:

1. The first thing to do is, of course, ping the destination and get the first piece of information of the communications line delay. Look at the How it works... section to see how it should be done.
2. Check for the delay variations, which can happen due to the following reasons:
   • A non-stable or busy communication line. In this case, you will see delay variations using the ping command. It will usually happen on lines with a narrow bandwidth, and in some cases on cellular lines. ...