Re: [lwip-users] Send buffers

[stephen]

Mr. Aldrich:

Try to increase this one: #define MEM_SIZE
Or maybe simply allocate a large buffer in your application to absorb TCP
traffic.
I guess flow control doesn't work under the situration that the source of
the traffic can't be controlled.

Stephen Chen

> Hi
>
> I now have lwIP working nicely with my application.  I do have one
> issue, however, that I would like to discuss.
>
> My application receives messages from another processor on the same card
> and transmits these messages to a PC over a TCP/IP connection.  My
> application cannot control the rate at which the other processor
> generates these messages.  My code simply discards the messages until
> the TCP/IP connection is established and then sends then down the lwIP
> stack.
>
> I have found that my processor can cope with the data rate from the
> other processor in steady-state, but for a short period after connection
> establishment I get lwIP send buffer overflow.  I assume that this is
> caused by the slow start algorithm.  After about a second, things settle
> down, and no data is lost.
>
> My question is how should I cope with this situation?
>
> I think that my only option is to increase the number of send buffers in
> lwIP to cope with the slow start.  What #defines in lwipopts.h should I
> modify?
>
> I would be interested to hear how applications should deal with this
> type of situation in general.  Does it imply that there should be some
> flow control at the application level?
>
> Thanks for your help,
>
> David
>
>
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