This is what I have done, but it does not seem to work! Please help. My router does not support UPnP

I enabled my DMZ and have my Xbox IP Address put into it, but nothing works.

I spent forever trying to solve the NAT problem when I playing on Xbox Live and finally learned to live with its issues. It was an issue that was pretty much unsolvable for me and my shitty Belkin router

I think some people just have that issue and have no way of solving it.

I could never get mine to work until I called up my ISP and complained about something unrelated and they sent me out a new modem; once I hooked up that new modem, no problems.

If you can't get a new modem, I would suggest getting a separate router if you don't have one already and put the modem in bridge mode; just let your router handle the connection, that seems to solve most problems I read online, I just couldn't figure out how to get my modem to bridge before I stopped caring about it.

This can be a pain. Have you verified the xbox has the same ip address since you have added it into DMZ? Your router will sometimes give a new ip address out. What make/model router do you have?

@jpr199: You might need to do some port forwarding. Look for your model here: http://portforward.com/english/applications/port_forwarding/XboxLive360/

and follow the guide.

If that doesn't work you could just get a new modem, which is what I did, eventually.

@jpr199 When I had NAT issues a couple of weeks ago, one of the responses (which I've quoted below) from here miraculously worked. Hopefully it works for you too!

1st make sure you have a static IP assignment for the xbox either by creating a dhcp assignment for the xbox's mac address or by statically assigning an ip to the xbox outside the dhcp scope you've defined but on the same network / subnet of course. next go to the single port forwarding tab under applications and gaming and forward port 3074, ,both internal and external, to your xbox's IP address. name the rule openNAT or something you will recognize. put a cheeck in the box to enable the rule and click save settings to enable. Your xbox should now run the xbox live test without complaint about the need for open NAT and gameplay should work just fine.