I've tried everything to get multiplayer working. I put my XBOX ONE in the DMZ. I opened proper ports. I moved my router next to my XBOX so I could connect it to the ethernet port. I can connect my XBOX to my Verizon 4G hotspot successfully and matchmaking works as expected. I've read that there is an issue with comcast wireless ipv6 architecture.. But it still doesn't work if I connect to the ethernet port.. This is crazy. Am I the only Comcast customer with this issue? Why didn't you guys test with Comcast routers before the launch. I'm about to send this XBOX ONE back to Amazon.