This port isnt written down in the readme maybe all the disconnctings
Its :
TCP 443
Open up the game log into multiplayer Go to desktop (Alt Tab) Click on Start(NO not consoles, lol!) and type and hit ENTER: CMD in the black CMD box you type: netstat
port 80 and 443 are allowed on most routers or proxied environments, so they should be the safest bet for keeping connection problems at a minimum. on the other hand this could cause problems if you're in a more closely monitored environment, where headers/packets get inspected...