Confused here, you marked this as Answered but then ask a question that leads one to think it's still a problem?!
Listen, I play more than one Multiplayer and setting-up ports for one game, the next, and the next and so on IMHO makes no sense.
DMZ Host is by far the one size fits all solution.
See picture for ALL of the 'complicated' settings (not) -> http://i.imgur.com/cpeq5uH.jpg
In order to get your NAT type from Strict to Open, you will need to establish a static IP address and port forward. If you have questions on how to port forward, please contact your ISP or the router manufacturer for additional support.
Here are the port numbers you will need Activision Support .
Yeah. Disabled my Windows Firewall and it went from Strict to Open here.