Vista - Xbox live priority.

ok so i know theres "port forwading"
but basicly i want my router to give my xbox live connection priority, or 1/2 of my bandwidth. following so far? im not sure how to i think its got some thing to do with QoS(i know what it is) but i want to make manualy give it priority because i dont trust what i cant see. i have already given my xbox DMZ that work pretty well
(went from red to yellow connection) and i know that the whole thing depends on a "host" which is lame because i always get the shot end of the stick, i just want to a even the fairness by getting a few more bars of connection for xbox.

Belking N1 vision version 1001, latest firmware,QoS enabled,20 and 40 MHZ 11b/g/n.

yes im willing to go for it, no i will not resort to using a screw driver or soldering iron. yes i have searched google

-lewismc-