[102950] in North American Network Operators' Group
RE: Tools to measure TCP connection speed
daemon@ATHENA.MIT.EDU (Darden, Patrick S.)
Mon Mar 10 08:42:30 2008
Date: Mon, 10 Mar 2008 08:41:34 -0400
In-Reply-To: <397392.14279.qm@web76302.mail.sg1.yahoo.com>
From: "Darden, Patrick S." <darden@armc.org>
To: "Joe Shen" <joe_hznm@yahoo.com.sg>, "NANGO" <nanog@merit.edu>
Errors-To: owner-nanog@merit.edu
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?=20
e.g. we want to measue the delay between the TCP SYN
and receiving SYN ACK packet.
Joe
=
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