First, you should check the status of the Call of Duty servers, as the servers may be down for maintenance. Links to the Call of Duty server status pages can be found on the homepage of this website.

If you are having a problem connecting to an online game, check the following:

Network Troubleshooting:

1. Disable any firewall or security features on your router.
2. Set port forwarding on your router to the IP (Internet Protocol) address of your Xbox 360. This game uses port 3074 (UDP/TCP). Additionally Xbox LIVE requires ports 80, 53 TCP (Transmission Control Protocol) and 88, 53 UDP (User Datagram Protocol).
3. Place your Xbox 360 into the DMZ of your router.
4. Disconnect your router and try the game. If it works regularly at this point something about your router may not be completely compatible with the specific needs of this game. Check with your router manufacturer and Microsoft's Xbox LIVE Connection Issues page for additional steps that may need to be done to resolve the issue you are having. You can also verify that you have an Xbox LIVE compatible router.
5. For certain Netgear routers (DGN-1000), change your ADSL multiplexing method from VC-Based to LLC-Based.

NOTE: If setting port forwarding or DMZ helps your connection issue, you may want to assign your Xbox 360 a static IP address within your home network. This can help to ensure that the configurations you made do not need to be done again.

NOTE: Many broadband internet modems are coming with routing capabilities built in. Please contact your internet service provider to determine if your internet modem has an integrated router. If it does, they should be able to assist you with the steps above for setting up your router.

Once you have verified that your network setup is not the cause of the issue, try running the Xbox Network Self Test to see how strong your NAT is currently set to. 

1. Turn on your Xbox 360 without a disc inside and go to Xbox Home.
2. Go to Settings and select System.
3. Select Network Settings.
4. Select a connection you would like to test.
5. Select Test Xbox LIVE Connection.
6. Select Yes to sign out of Xbox LIVE and let the test run. 

Once the test is completed you will be notified if there is an issue with your connection. If you select "More Info" you will be given information about your NAT type and some steps to resolve any issues with your connection. Once the test is completed you will be notified if there is an issue with your connection. If you select "More Info" you will be given information about your NAT type and some steps to resolve any issues with your connection.

Moderate and Strict NAT types may have issues connecting to online matches. You may get the error "Notice - The game session is no longer available." If you do then enabling UPnP (Universal Plug and Play), forwarding port 3074, or placing your Xbox in your router's DMZ may resolve this issue. Please consult your router documentation for instructions on how to do this.