How can I get a better connection to my xbox live with a belkin router?

I have a Belkin F5D8230-4 router, but my NAT is always moderate and I lag in every game I play. I am using an ethernet cable to connect my xbox 360 directly to my router (less than 100 meters away). Every time i connect to COD 4 or something, I lag like no other and my connection is never good.How can I get a better connection to my xbox live with a belkin router?
You need to make your NAT Open. Do this by opening ports 88 and 3074 in your router.



First you need to setup a static IP for your xbox in your router.



Then forward the ports.

http://www.portforward.com/english/route