TCP flow controll question

[Alexander D. Tarkhov]

Hello, rtems society,

We use RTEMS 4.0.0 with mips64orion p4650.
We have succeded in compiling network support for our bsp, 
but there seems to be a problem somewhere.

Sometimes in some projects mbuf clusters are filled up critically 
due to some errors :)
In our case it implyes "rtems panic" as a consequence.
The simplest solution is to increase the initial amount of mbuf memory.
>From that point my question arises:

In our partiqular case we deal with a faulty Data Link Layer (non
ethernet),
so that it may take several retries to transmit a TCP packet.
IP stack allows us to call send() as many times as we want, not
bothering
wether previous data are really away or not. As a result we get all our
great amount
of mbuf memory filled and return to our good-old "rtems panic" again.

Is there any way to know, if data is still in the system?
Other words: Is there any way to controll the flow of data through a TCP
socket?

Thank you for your help,
all comments are welcome.

Alexander Tarkhov

P.S. I don't mean the error is located in stack or something, 
I just want to overcome it somehow :)