protocol priority

[i18rabbit at hotpop.com]

with FreeBSD 4.10 functioning as a 'ppp -nat' LAN server,
is there anyway to prioritize the processing of protocols?

for example, i am grabbing nntp data, and i want it at a much
lower priority than http data - when i use my browser, i want
to see a 90/10 ratio of http/nntp packets in tcpdump on the
LAN server.  i never heard of this being done, but it would
be nice.  running 'nice' on a client doesn't seem to change
anything so far as this goes.

please copy any replies off the maillist, thank you.