general options for getting your NAT Status to Open
There are four ways to overcome a Strict/Moderate NAT setting when using a router. I have listed them in the order of preference:-
1. If you have an Xbox Live Certified router, use the certified firmware for your router
2. Use UPnP. If your router supports this. Turn it on. The router will work out the ports it needs to open for Xbox live. If your router does not have this feature, check the manufacturers website for the latest firmware. (also make sure portforwarding and/or DMZ is turned off as they interfere with UPnP)
3. Port forwarding (look up your router here then follow the instructions for Xbox Live 360)
http://www.portforward.com/routers.htm
4. Use a DMZ (De-militarized Zone)
The DMZ (De-militarized Zone) is area that sits outside of your routers firewall. Don't worry though your not at risk with your Xbox
IMPORTANT
Do not mix and match portfowarding with UPnP and/or DMZ. Each of the methods should be used on their own. Do not turn on UPnP and expect to be able to setup a DMZ or Portforward.
ortforwarding
If UPnP is not an option for you, or you have tried it and it does not work. Look up your router here then follow the instructions for Xbox Live 360. When you port forward the ip address that you need to forward to is the ip address of the Xbox. It is always best to use a static ip address when portforwarding, see this section for more details.
DMZ
Consult your router documentation to find out how to put your Xbox IP Address in the DMZ of your router. It is always best to use a static ip address when using a DMZ,
Also what router have you got??? is it a belkin?