Re: SV: [lwip-users] TCP payload is doubled

[Kieran Mansley]

On Thu, 2009-10-22 at 11:18 +1300, David Empson wrote:
> Kieran Mansley wrote:
> > I was a bit wrong there.  I've taken another look at the code and this
> > change in behaviour is intentional.  There were two changes in 1.3.1:
> > - only send an explicit window update if the change is greater than
> > TCP_WND_UPDATE_THRESHOLD.
> > - only change the window advertised (including in normal ACKs) if the
> > change is greater than 1 MSS.  This is silly window avoidance, and
> > designed to prevent the sender getting small amounts of window and then
> > sending small packets.
> 
> The description of silly window avoidance in RFC1122 (section 4.2.3.3) says
> that there is supposed to be a second test.
> 
> The threshold to advertise an increase in window size should be the lesser
> of MSS and WND/2 (assuming the recommended fraction of 1/2).

Sounds like a good change.  Could you file a bug for this?

Kieran