Hey Keapwn,
The console NAT represents your communication to the Xbox Live servers, whereas the In Game NAT represents your communication with the Call of Duty Ghosts servers. Thanks for letting us know how your connection is set up. Are you able to play on a wired connection? As with a wireless connection, some packets may be lost or corrupted during transmission. If not, you may want to try prioritizing your console on the router channel settings as well as disable the iPv6 setting. Also, do you have a static ip set up for your console? This will help to create stability and help you avoid having to reconfigure your ports in the future. Just to be sure, did you make sure to disable UPnP and DMZ since you are currently Port Forwarding?
Here is a list of ports that may come in handy:
Xbox Ports:
53, 80, 3074 TCP
53, 88, 500, 3074, 3544, 4500 UDP
Call of Duty Ghosts Console Ports:
80, 81,443, 3074, 5223 TCP
36081, 3074, 3075, 3478 UDP
Thanks,
^AJ