Good point as it uses an additional port not required for standard Xbox One Live use. The additional port for BO 3 is 3075 for both TCP and UDP. (whilst we're at it XBox One Live requires: TCP: 53, 80, 3074 UDP: 53, 88, 500, 3074, 3544, 4500)
Just looked at 3 different servers all of which traceroute doesn't complete but ends in x.y.z.msn.net ( 40.127.196.35 23.101.52.46 65.52.229.40 ) all were correctly marked with tos 0x0a. I doubt Plusnet (s suppliers) rely on ports - people with multiple devices get different ports anyway one of mine just now was 23.101.52.46.31005 > myip.3101 I always thought that those port lists "out there" should really spell out what's needed inbound and explain that normally outbound will just work rather than give a confusing list - you really don't need to open dns, www or most of the others inbound to use xbox live. From looking at UPnP logs after asking for external IP address a single xbox only opens 3074 UDP and BO3 on the one opens 3075 UDP. If it can't get those because they have gone it will use semi random ports you won't find listed anywhere. It's possible that using xbox for more than gaming will open more - that I haven't tested and on the one I haven't tested any other games yet.
