TCP/IP problem : 'Still waiting for mbuf cluster'

Sergei Organov osv at
Wed Sep 13 14:44:30 UTC 2006

"Sylvain Prestavoine"
<sylvain.prestavoine at> writes:

> ----- Original Message ----- 
> From: "Sylvain Prestavoine" <sylvain.prestavoine at>
>> But why the problem appear when the TCP client send one message window
>> update or
>> window is null ?
>> Why that disrupt the RTEMS stack IP ?
>> The flow control shouldn't have cause this effect, no ?
>> I don't understand it.
> Is it the 'silly window syndrome' ?
> Because this problem appear with an client software particularly slow.
> In use with telnet program, it working properly...
> (  my application send a lot of byte after receive a command ).

When client reads the data fast, your RTEMS app doesn't use all the
memory configured for socket buffers, I think, thus it continues to work
even though the socket buffer size limit is high.

-- Sergei.

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