Re: [PATCH] fix tcp_default_win_scale.

[Stephen Hemminger <shemminger@osdl.org>]

On Tue, 6 Jul 2004 13:17:31 -0700
"David S. Miller" <davem@redhat.com> wrote:

> On Tue, 6 Jul 2004 20:58:56 +0200
> Jan-Benedict Glaw <jbglaw@lug-owl.de> wrote:
> 
> > On Tue, 2004-07-06 11:47:41 -0700, Stephen Hemminger <shemminger@osdl.org>
> > wrote in message <20040706114741.1bf98bbe@dell_ss3.pdx.osdl.net>:
> > 
> > > I propose that the following that will avoid sending window scaling that
> > > is big enough to break in these cases unless the tcp_rmem has been increased.
> > > It will keep default configuration from blowing in a corrupt world.
> > 
> > I'm not sure if this is the right way to react. I'd think it's okay to
> > give the user the possibility to scale the window so that it works with
> > his b0rk3d firewall, but default behavior should be to do whatever the
> > protocol dictates/allows.
> 
> I totally agree, and that's why the sysctl is there for people to
> tweak as they desire.
> 
> Jan, any particular reason you removed so much stuff (in particular
> netdev@oss.sgi.com) from the CC: list in your posting here?

The point is we are sending a bigger window scale then we need to.
The maximum receive window is limited by tcp_rmem[2], so we only need to
allow that much.  Having a different sysctl just for that is unnecessary and
potentially confusing.

The default tcp_rmem[2] is 174760, so we only need a wscale of 2 to represent
that. We were sending 7.