[lwip-users] Re: [lwip] MSS and config generally

[Dirk Koopman]

On Thu, 2002-06-06 at 15:50, Kieran Mansley wrote:
> On 6 Jun 2002, Dirk Koopman wrote:
> 
> > Can you get me some pointers as to how to alter the MSS segment size
> > successfully?
> >
> > I have recently ported lwip to an embedded platform and am having the
> > following two symptoms:-
> >
> > 1. I have an *incoming* segment size of 128, ie I connect to an external
> > site using TCP (native interface) and get back data in 128 byte gobs,
> > one per datagram.
> >
> > 2. It is EXCEEDING slow, this may well be a timing error of some kind on
> > my (ie even though I think I am; I am not calling the timer routines as
> > often as I think I am).
> >
> > Does this sound familiar to anyone and what are the issues (and
> > parameter settings) in lwipopt.h to get larger MSS sizes (or to switch
> > it off).
> 
> Alter TCP_MSS (in lwipopts.h) to your requirements?

Tried that. Made no obvious difference.

> 
> Also, make sure that the config options related to this are set to
> sensible amounts.  Your poor performance could be due to insufficiently
> sized TCP_SND_BUF, TCP_SND_QUEUELEN or TCP_WND
>

Given say a 1024 byte MSS, what would say the other parameters should
look like?

Dirk


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