one uses the command tc (traffic control AFAIK) for this kind of thing, its part of the package iproute2

check its documentation

the docs are not very clear IMO, but with some efforts you'll get there, I'm willing to post my TC scrip but it only shapes the outgoing traffic.

cheers,

Alaa

http://www.manalaa.net

"u know i once dream that the office of mobinil is from el 7`os :S and the one that answer u and tell u rasidak a girl called ghada"