Go to 'Network Settings' on the XMB and select internet test.
It will run a quick test on your PS3 and tell you your NAT type.
A NAT type of 1 or 2 is the most desirable with 3 potentially blocking communication between you and other players, as I understand it.
If you change the security settings on your router to medium or low that often drops the NAT type down to a 2 and if you get the password from your internet provider and enter it during the internet setup stage that can drop it to a NAT 1.








