Re: [lwip-devel] TCP MSS question

[address@hidden]

Kieran Mansley schrieb:
> On Sun, 2007-10-28 at 19:19 +0100, address@hidden wrote:
>   
> > Two questions about our TCP implementation:
> >
> > - RFC 1122 says TCP should send with an MSS of "536 if no MSS option is 
> > received" (chapter 4.2.2.6). We send with our configured TCP_MSS 
> > instead. Since even Windows sends with 536 (btw: what does linux do?), 
> > we should maybe change our code to meet the RFC?
> >     
>
> Yes, I think we should change to use a max of 536 in those cases.  It's
> perhaps a bit out dated for local area networks, but can still make
> sense when running over longer links.
>   
That was exatcly my point of view, too.
>   
> > - tcp_parseopt() doesn't allow a send MSS (advertised by the remote 
> > side) to be larger than the configured TCP_MSS. Is this included in 
> > order to configure memory usage or does it have other reasons?
> >     
>
> I'm happier leaving that one as it is, as I suspect it does make
> configuring memory usage simpler if we can know in advance what the
> upper limit will be on received segments.
>   
Didn't want to change that, only asking questions :)
And the answer is what I thought, too, so I'm OK with it, of course.

Simon