I was recently trying to play Halo 3 with my friend, and it said I couldn't connect because my NAT setup wasn't compatible. It said I had the lowest kind. The NAT affects your connection with other people in case you forgot. I went to Test Connection and surely enough, NAT, down at the bottom, was set to Strict. I was wondering if anyone knew how to fix this.

what is NAT

I you do not know, I would appreciate if you wouldn't comment. This isn't an overall discussion of NAT, it is just a question I have about it. I have explained it to the best of my knowledge. I was hoping someone would know what I am talking about.