RE: Tools to measure TCP connection speed

["Darden, Patrick S." <darden () armc org>]

Best way to do it is right after the SYN just count "one one thousand, two one thousand" until you get the ACK.  This 
works best for RFC 1149 traffic, but is applicable for certain others as well.

I don't know of any automated tool, per se.  You really couldn't do it *well* on the software side.  I see a few 
options:

1.  this invalidates itself, but it is easily doable: get one of those ethernet cards that includes all stack 
processing, and write a simple driver that includes a timing mechanism and a logger.  It invalidates itself because 
your real-life connection speeds would depend on the actual card you usually use, the OS, etc. ad nauseum, and you 
would be bypassing all of those.

2.  if you are using a "free" as in open source OS, specifically as in Linux or FreeBSD, then you could write a simple 
kernel module that could do it.  It would still be wrong--but depending on your skill it wouldn't be too wrong.

3.  this might actually work for you.  Check to see how many total TCP connections your OS can handle, make sure your 
TCP timeout is set to the default 15 minutes, then set up a simple perl script that simply starts a timer, opens 
sockets as fast as it can, and when it reaches the total the OS can handle it lets you know the time passed.  Take that 
and divide by total number of connections and you get the average....  It won't be very accurate, but it will give you 
some kind of idea.

Please forgive the humor....

--Patrick Darden



-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of
Joe Shen
Sent: Monday, March 10, 2008 5:00 AM
To: NANGO
Subject: Tools to measure TCP connection speed



hi,

  is there any tool could measue e2e TCP connection
speed? 


  e.g. we want to measue the delay between the TCP SYN
and receiving SYN ACK packet.


 Joe


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