We are happy to help as much as we can, but there are just some questions we can't answer.
Here are some useful links to look at to help you further.
Here you'll find a breakdown of what UDP and TCP ports Xbox LIVE communicates through, and how you can set up port forwarding to open them up.
Find out what Microsoft says about the symptoms associated with NAT related errors and what you can do to fix them.
This is a general Xbox LIVE support page. Start here if you're having Xbox LIVE connectivity problems.