Hi Ronnie,
Thanks for your reply.
Could someone has used the tcptrace output file (in xpl format) to obtain a csv file which has the throughput value in different time intervals (say time interval of 5s) ?
Thanks for your help first.
BR
Victor
-----Original Message-----
From: ext Ronnie Sahlberg [mailto:ronnie_sahlberg@xxxxxxxxxxxxxx]
Sent: Tuesday, April 01, 2003 5:16 PM
To: Lee Victor (NET/HongKong); ethereal-users@xxxxxxxxxxxx
Subject: Re: [Ethereal-users] TCP performance measurment in csv format
You should be able to do some tethereal + perl magic to do that.
Something similar is already available in ethereal if you just want to
verify that
bulk tcp transfers are behaving properly:
The 5 second method to verify if the tcp layer is a-ok or not for optimal
throughput for bulk transfers:
==================================================
Select one packet in the direction of the tcp bulk transfer performane
analysis.
Select Tools/TCP Stream Analysis
Apply eyeball to graph:
* If after zooming in looks like a straight line from bottom left to top
right corner
everything is a-ok on the tcp layer.
* If you get a staircase where the height of each step is approximately the
same height
you have a problem with tcp window size being too small.
The width of each step should only vary a little and is the RTT for the
flow.
This effect is caused by having the tcp window smaller than what can be
transmitted end-to-end during one RTT and this small tcp window size is
capping throughput.
Increase the tcp window size to compensate for the end to end latency.
* If you get a staircase with different heights of the steps and also widely
varying lengths of the steps, with some steps being very long/wide. Then
what you see is normal (i.e. non-fast) tcp
retransmissions which kills your performance.
Ivestigate what is causing the congestion/packet-loss and reduce it and
performance will
be enhanced.
This often means that the tcp window size is too high and that this causes
bursts that will overflow
a buffer somewhere.
----- Original Message -----
From: victor.lee
Sent: Tuesday, April 01, 2003 12:12 AM
Subject: [Ethereal-users] TCP performance measurment in csv format
Hi,
I would like to know if there is a good method to calculate the end-to-end
TCP throughput against time and converted the result into a csv file in
other for further Excel post-processing.
Cheers,
Victor Lee
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