I was reading an earlier articale here and ran across this
https://www.afp548.com/article.php?story=2005041722220621
Firewall
The first thing you notice about the Firewall Service is that its interface in Server Admin has been cleaned up a great deal. It’s now much easier to figure out what your rules are doing and how to set them up. If you dive under the hood though you will find a tasty nugget in the fact that ipfw now includes dummynet as well. Dummynet has long been a part of ipfw on other BSD based platforms, but has long been missing from Mac OS X. Now that we have it you can use your Mac OS X Server for doing things like traffic shaping and bandwidth management. “Where the heck is dummynet?” is a very common question to people moving to Mac OS X and now it has an easy answer.
It looks like a dummynet could be the answer, but being a dummy i have no idea on how to use it. 🙂 But here are some quick googled links.
freeBSD manual
http://www.gsp.com/cgi-bin/man.cgi?section=4&topic=dummynet
freshmeat
http://freshmeat.net/projects/dummynet/
Now that you bring it up, I might have to get this working on my own server….
good luck demonas!
Rick