Halo 4 and not being able to connect to others games on Xbox 360 :Z

[DeViLzzz]

I think I have changed my settings properly with my router and even assigned a static IP for the Xbox 360 so I was wondering if someone wanted to invite me to a Halo 4 game or something else to see if I got this right. My router is the DIR-615 (POS). Today when I tried to join a friend's game and they had open NAT I could not join. I had medium NAT and have since tried to rectify the situation. Funny thing is I should have still been able to join their game with medium NAT I believe.

[Helltech]

I have to have open nat to do anything in Halo 4. I had to put my Xbox in the DMZ.

[DeViLzzz]

Well I hope I made changes that will fix things cuz I don't like that I missed out playing with my sister's kid over this networking bs. As for DMZ I think I dealt with that today. Is it where you leave certain IPs assigned to certain devices wide open for traffic ? I think I did that earlier but not sure if I shut it off. :Z