Porting TCP/IP stack

[Robert Pleh]

The TCP/IP stack included in RTEMS simce to be to big for our application
(RAM limitation is 512K).Target used is 68360 processor.
I think we could live with 150k stack size (code+data+BSS).

Has anyone ported some smaller TCP/IP stack to RTEMS?
I'm thinking of porting lwIP stack (http://www.sics.se/~adam/lwip/) to
RTEMS. 
Would there be a lot of work to port such a stack to RTEMS? Could someone
give me some guidelines?
Or would it be easier to try to reduce the size of included BSD stack?

Regards,
Robert