Don't know if it will work with everyone, but I had an issue with CoD disconnecting during gameplay and the only issue I could find was that the Latency was too high.
I was wrong.
Turning the wifi setting on my Superhub 2 to compatibility 54mb rather than performance has solved the issue, yes the stats now showing on the Xbox for my connection are now worse, but, I have found no lag issues though and the disconnection issue is also gone.
Hope this helps anyone
Note: Also using a static IP and port forwarding while doing so.