Subject: Re: Congestion Avoidance Monitoring Tools

From: Stephen Hemminger <[email-masked]>
Date: Fri, 21 Apr 2006 08:19:17 -0700

On Thu, 20 Apr 2006 22:26:14 -0700
Piet Delaney <[email-masked]> 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
> 

2.6.13 still had lots of problems, things didn't really get working
right till 2.6.15 or later. Especially with TSO.

I have a tool using kprobe's see http://developer.osdl.org/shemminger/prototypes/tcpprobe.tar.gz
I try to keep it up to date with current kernel and build process, last used it
on 2.6.16.