and nope - I wouldn't turn on my router's UPnP function. Why?
To solve the MW2 issue you need to do three things only:
(described for PC but i guess it basically works for xbox and PS3 too)
- make sure your router always assigns the same tcp-ip address to your computer, open your PC's command prompt and type: ipconfig /all - the physical address is the mac address you'll need for this step - log into your router and look for "reservation" now reserve the address for your PC.
- in your router, look for something called Port Forwarding then add an entry (aka add a custom service) with the following value: Forward UDP / port 28960 / "to your PC's tcp-ip address"
- make sure your firewall isn't blocking the incoming traffic to your application or game. Check this in the firewall advanced dialog > inbound rules
Actually you might go nuts configuring your devices! Ask your befriended computer wiz to help you with above's steps, the pro knows immediately what to do. Keep your router password and your admin account handy before he arrives at your home.
Why do you have to go through all this?
These days almost all broadband connections make use of a router. With it's default setting internet works fine, but you won't be able to host services like webservers or games etc. Generally that's a good thing because it keeps your comp environment a bit safer from outside attacks. But it usually prevents you from hosting a game.
Your ISP lends you 1 TCP-IP address every time you connect to the interent, the router grabs this address. Let's call this address "A"




















