Troubleshooting TCP performance tutorial

Date: Fri, 17 Sep 2010 20:06:09 -0400
From: "Abel Alejandro" <>


This past week I have been trying to find the root cause of tcp
performance problems of a few clients that are using a third party metro
Ethernet for transport. RFC2544 tests (Layer 2) and iperf using UDP give
good symmetric performance almost 100% the speed of the circuit. However
all kind of TCP tests result in some kind of asymmetrical deficiency,
either the upstream or downstream of the client is hugely different. The
latency is not a huge factor since all the metro Ethernet connections
have less than 2 ms.

So the question basically if is there a good tutorial or white paper for
troubleshooting tcp with emphasis of using tools like Wireshark to debug
and track this kind of problems.


You might look at A lot of it is aimed at very
large volume data transfers, but quite a bit is relevant to all TCP

+1 Excellent resource.