Re: Debian on ThinkPad T41p: a report and a question

[Martin Weinberg <martin.weinberg@comcast.net>]

On Mon, Sep 06, 2004 at 05:40:52PM -0400, Martin Weinberg wrote: 
>
> The one problem I am having is quite odd: I find that remote sessions
> through a ssh tunnel hang intermittently after a few kilobytes.  My
> old laptop (a Sony Vaio) also running Sarge with the same setup and
> wirelessly attached to the same router but kernel 2.6.7 works fine.
> Other network connections seem to work during an episode of hanging.
> If I am patient, most often a future ssh connection will work (and
> then continue to work until terminated).  Does anybody have a clue?
> I'm stuck on this one.

OK, for the record, the problem is the interaction between window
scaling in Linux kernel 2.6.8 and my router.  The latency for my
remote connections is large enough that the kernel attempts to use
large windows and this *appears* to cause my router to get confused.
If I turn off window scaling, e.g.

echo 0 > /proc/sys/net/ipv4/tcp_window_scaling

then all is well.

--Martin