From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piet Delaney Subject: Re: Congestion Avoidance Monitoring Tools Date: Fri, 21 Apr 2006 00:25:27 -0700 Message-ID: <1145604327.5901.16.camel@piet2.bluelane.com> References: <1145597174.12413.17.camel@piet2.bluelane.com> <1145599196.2534.38.camel@penguin> <200604210857.19084.ak@suse.de> Reply-To: piet@bluelane.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Piet Delaney , Tom Young , netdev@vger.kernel.org, linux-net@vger.kernel.org Return-path: Received: from mse2fe2.mse2.exchange.ms ([66.232.26.194]:50451 "EHLO mse2fe2.mse2.exchange.ms") by vger.kernel.org with ESMTP id S1751224AbWDUHZb (ORCPT ); Fri, 21 Apr 2006 03:25:31 -0400 To: Andi Kleen In-Reply-To: <200604210857.19084.ak@suse.de> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 2006-04-21 at 08:57 +0200, Andi Kleen wrote: > On Friday 21 April 2006 07:59, Tom Young wrote: > > On Thu, 2006-04-20 at 22:26 -0700, Piet Delaney wrote: > > > I'm upgrading our 2.6.12 kernel to 2.6.13, which includes significant > > > congestion avoidance code additions and changes. I was wondering if > > > there are any tools folks can recommend for testing the kernel to make > > > sure the congestion avoidance code is operating correctly. For > > > example the displaying of the congestion window as a function of time > > > while undergoing convergence. For causing congestion I could modify > > > a kernel to discard packets once in a while on a lab gateway and hit > > > it with iperf. HP's netperf looks interesting. > > > > > > Any suggestions? > > > > > > > > > -piet > > > > > > > Hi, > > > > Try having a look at the output of 'ss -i' (you may need to update to > > the latest iproute2 tools). You could either try and parse the text > > output of that or use the same inet_diag interface that ss uses to poll > > for the data it at regular intervals. > > Another way is to use tcptrace on a tcpdump file > (http://jarok.cs.ohiou.edu/software/tcptrace/) > It finds a lot of statistics about the dumped TCP connections. Tcptrace looks pretty good, graphing the sequence numbers as a function of time was one of the features I'm looking for. > > Newer ethereal also has some TCP plotting functions that are useful. > They don't display the congestion window directly, but you can see it indirectly. I never tried the ethereal graph facility, looks like another great idea. Thanks, -piet > > -Andi -- --- piet@bluelane.com