I read this on the monowall mailing list, it was posted by Michael Graves
"Sure. Although it helps to know what protocols you run through m0n0. My Asterisk server places outgoing calls via IAX2 and accepts incomming calls via both IAX2 and SIP.
You absolutely have to start with a real world measurment of your connect speeds up and down. Your traffic shapping must not saturate either of those or the benefit will be lost.
The use the Magic Shaper Wizard on the Traffic Shaping tool. This will setup basic rules, pipes and queues. You should have two pipes; Total_upload & Total_download.
Here's where I change the setup a little. I add a third pipe called Dedicated_IAX_upload. I split my upload data rate between Total_upload and Dedicated_IAX_upload. In my case on Covad ADSL with a measured 650kbps upload I set my total upload speed for only 600kbps. I then assign 384kbps to pipe 2 (Total_upload) and 256kbps to pipe 3
(Dedicated_IAX_upload.)
In essence, I full time assign about 40% of my outbound bandwidth to the voip stuff.
Then in the rules section of traffic shaper I add two rules for my Asterisk traffic. All UDP traffic from the servers IP to the wan is driected to pipe3. All UDP traffic from the wan to the server is assigned to Queue 8 which is High_priority_download.
Of course you need firewall NAT and port forwarding settings in place as well. The traffic shaping isn't port specific in my arrangement.
I've had my Asterisk & m0n0 system in use for about 2 years. You need to understand that traffic shaping won't cure bandwidth issues, but it will make some situation more acceptable. I found that adding G.729 codecs to my server was also very helpfull in reducing the demand for bandwidth.
Also, I don't use any p2p stuff beyond Skype...which I'd rather not use but many of my overseas coworkers are addicted."