actually, since you need it for a wireless network you should find the following howto useful :
the script descriped in the article "dial up admin" is very good for controlling bandwidth and other stuff
you may find more info here :
and after excessive search, I found a chinese howto, translated from google here :
if this helped you please let me know..
I am trying to get these stuff works so I can contribute a howto here about it
about Mikrotek, I used it before, actually I coud'nt deal with it, if you can help this would be good..
if any solution worked with you it is a nice idea to contribute a howto about it here, this will get you a membership for 12 months (worths 50$ I think) more info could be found here :