i have spent weeks tweaking my connection and used to have an open NAT on my xp based pc but settings seem the same and its strict. ive tried opening ports (80) and (3054) that i read somewhere and it still doesn't work. any ideas folks as its limiting my halo3 experience.

the answer is by martinoneil216 :
Hi

I had the same issue with my xbox 360, the best advice I can give is to check out the guides on http://www.portforward.com/. They list most types of routers and applications and take you through the config step by step.

You can view the guides by the router you use then you select xbox live and it will show which ports to open etc, http://www.portforward.com/english/routers/port_forwarding/routerindex.htm.

Hope this helps