I just got Halo 3 and instantly tried to play a game with my friend who lives in New York. Neither of us could connect to each other because of our NAT settings . I have very limited knowledge of any wireless stuff other than my AirPort Express Base Station with AirTunes has made my life very easy up until this point. I have never had a problem using my Xbox 360 to connect to him or anyone else before for any other game. I went to the bungie website and this is what I found. Q: What is NAT and why do I care about it? A: In extremely simple terms, NAT (Network Address Translation) helps determine how your router interacts with the rest of the internet. If your NAT settings are restrictive, you may have problems connecting to other players. To test your settings, go to the Xbox 360 Dashboard and test your connection. At the bottom of the test results, you will see your NAT Type. You want it to say Open if it says Moderate or Strict you may experience some problems. If you're NAT settings display 'Moderate' or 'Strict,' you should consult your router's documentation, either online or in the instruction manual. If anyone has any idea how I can change my setting on my AirPort Express Base Station with AirTunes to "open" I would be very appreciative .