tcptrace a TCP dump file analysis tool written by Shawn Ostermann
at Ohio University. It is NOT a packet capture program. It reads
output dump files in the formats of several popular packet capturing
programs: tcpdump, snoop, etherpeek, and netm.  It can also output
(ie, convert thus converting to) tcpdump format files.

For each connection, it keeps track of elapsed time, bytes/segments
sent and received, retransmissions, round trip times, window
advertisements, throughput, etc.  Its output format ranges from
Simple to Long to Very Detailed.

It can also produce three different types of graphs, as follows: 

   Time Sequence Graph 
     This is the format that Tim Shepard started using at MIT some
     years ago. It shows segments sent and ACKs returned as a
     function of time.
   Instantaneous Throughput 
     This format shows the instantaneous (averaged over a few
     segments) throughput of the connection as a function of time.
   Round Trip Times 
     This format shows the round trip times for the ACKs as a
     function of time.

The graphs produced are viewable only by Tim Shepard's wonderful
xplot program (in math/xplot).

WWW: http://www.tcptrace.org/