Subject: Re: Possible BUG in IPv4 TCP window handling, all recent 2.4.x/2.6.x kernels

From: John Heffner <[email-masked]>
Date: Fri, 2 Sep 2005 10:10:18 -0400

On Sep 2, 2005, at 10:05 AM, [email-masked] wrote:

> This particular Win2k sender sends _only_ real-time data, it's not 
> capable of rewinding. So it's always sending small packets, from start 
> to finish, yet the problem still occurs.
>
> Note that even real-time data can end up generating a stream of 
> full-size packets occassionally. It's just very unlikely they would 
> occur at the start of the flow, as market data is very thin in the 
> pre-market open hours.

The rcv_ssthresh growth can actually take place anywhere in the flow, 
not just at the beginning.

>> But, that window clamping should fix the problem, as we recalculate
>> the window to advertise.
>
> Patches for testing are very much welcome...

Have you tried increasing the size of the receive buffer yet?

   -John