Re: [lwip-users] again: throughput problem

[K.J. Mansley]

On Fri, 2004-03-26 at 12:35, address@hidden wrote:
> Hi Kieran,
> 
> thanks for your hints. I have changed my configuration and I could
> raise the throughput (I had to increase the parameter
> TCP_SND_QUEUELEN).

I should add that the TCP_SND_QUEUELEN is something of an lwIP oddity. 
We have a two limits on the send queue - one is the (normal) number of
bytes in the queue, and this is controlled by TCP_SND_BUF.  The other is
the number of buffers in the queue, and this is controlled by
TCP_SND_QUEUELEN.  This is (I think) to prevent all your buffers being
put on the send queue, leaving none to receive packets.  However, it's
important to understand that increasing the one that is *not* the
current limiting factor will have no effect until the other one is
increased to the level where it is no longer the limiting factor.

Hope that's clear!

Kieran