We're excited to announce that we've fully migrated the Xbox Forums to their new home, here on the Microsoft Community forums!
As of today, going to forums.xbox.com will redirect you here to the Xbox area of the Community forums. We've moved all of your existing threads over so you can continue and start conversations with the new forums experience.
We sincerely appreciate the feedback you have provided over this transition and can't wait for you to check out the new Xbox Forums!
What I've usually done is go here:
support.xbox.com/.../nat-type-strict.aspx (the official support page on the xbox.com website) and follow the instructions laid out. Black Ops may have its own ports to be opened like others have suggested, but opening the Xbox 360's own needed ports may
easily fix the issue. Not opening the 360's needed ports while doing so for Black Ops ports may not solve the problem. Past the instructions I've linked to I have never had any more problems, and it has fixed the ones I have had. Good luck!
I gotta get a new router, the xbox IP keeps changing and I have to forward ports to a different IP. Some days it's 100, other 101, 102. I'm running DHCP with 5 users. I heared I need the new UPnP. I haven't heard of this QoS.