Yooo Shane,
If you are behind a router, you have to forward following ports:
| Ports |
UDP | 11001-11004 |
TCP | 11001-11004 |
If that dosn't help, you could try to forward TCP 27900 and TCP 28900 aswell.
http://portforward.com/
Go there and select your router and you will get a step-for-step manual how to forward ports. (Skip advertisement)