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my brother and i both have Comcast but cant join eachothers games when on xbox live...we can join any game but not one with eachother in the room...his connection is much faster than mine but i was told that didnt matter...then when i tried to open the ports in this broadband modem it took me days to find out broadband modems cant have the ports opened by a pc only routers can be opened/ forwarded...so i dunno wut to do...should i get a new/different modem from Comcast? maybe get a router?  please help i been going crazy for weeks


My brother and i cant party up, voice chat, or invite eachother to games...OH AND MY BROTHER HAS NO PC TO CHECK HIS CONNECTION BUT LIKE I SAID HE HAS SUPER FAST SPEED WE JUST CANT BE IN THE SAME ROOM/LOBBY

When you try and join each other, do you get a message saying something about your NAT connection?
What kind of router are you using(if your using one)?
Have you made sure your UPnP is enabled?