u just set ur wifi to no dhcp

and ur xbox must set to an ip
E.G.

IP Address: 192.168.0.88 ( the ip must be same grp with ur router)
Sub: 255.255.255.0
Gateway: (point to your router ip)

Dns 202.188.0.133
Alt : 202.188.1.5
and then ur router need to do this

Port forwading



(Each Router will be vary)

set ur xbox ip and the port u need to forward... (which i forgot... maybe someone can post it up or give me some time to check back)

Hope this help...