D-Link Wireless N Router (DIR-615) (product link) After much hassle and bouncing around with Xbox Live, Rogers, and Different Router Companies we finally found a router that works. We have two Xboxes one that hooks up via wireless network adapter and one that is hard lined to the router.
We went through all of the port forwarding and dmz and everything they will run you through but the problem was the routers we were using. We picked this one up from Future Shop (help desk recommended it) took it home after trying two that were over $200 i thought no way this $70 one was going to work, i was wrong. It took about 10 min to setup, i didn’t have to do any dmz, no port forwarding or anything and now both xboxes can play on live, halo 3, halo 3 odst, and nhl 10 without any problems or nat issues.
So if your having the same problem where one Xbox is losing it’s live connection give this router a try it worked great for us.