If you are playing on PC, please enable the following online ports on your connection:
TCP: 80, 443, 9988, 17502, 20000-20100, 22990, 42127
UDP: 3659, 14000-14016, 22990-23006, 25200-25300

If you are playing on PS3, please enable the following online ports on your connection:
TCP: 80, 443, 9988, 10000-10100, 17502, 42127
UDP: 3659, 14000-14016

If you are playing on PS4, please enable the following online ports on your connection:
TCP: 80, 443, 1935, 3478-3480
UDP: 3478-3479

If you are playing on Xbox 360, please enable the following online ports on your connection:
TCP: 53, 88, 3074, 80
UDP: 53, 88, 3074

If you are playing on Xbox One, please enable the following online ports on your connection:
TCP: 53, 80, 3074
UDP: 53, 88, 500, 3074, 3544, 4500

For specific instructions on how to open your ports, please visit http://www.portforward.com/ or contact your router manufacturer