Same "/

Been having the same problem. Was able to get in after 2am pst yesterday morning and a couple times during the day, but lots of server and host disconnects. I'm led to believe it's due to server overloading because of the release of Black Ops 2. Most of my friends list was affected too, although, periodically some of them can get in also.

i have been having this issue since BO2 came out, the only way i can get on is if one of my friends invite me to a game. it won't connect itself at all. XBL works fine on ALL other games only mw3 is not working.

there is an issue here an it is not on our end. my NAT type is always OPEN so that ain't it.

Customer support finally got back to me. Turns out that there is a technical issue between the MW3 servers and Telus. They believe it has been resolved, or will be shortly. Not sure if this helps everyone, but hopefully we'll all be able to log in and kill each other with ease again.