Best thing to do is log into your router and check settings,
make sure settings listed as UpNp are enabled and some routers have firewall settings check them for Nat redirect or the upnp settings, or you can use port triggers search for your games ports and add them to the list. Port Trigger:: start 88 end 88- triggered port start 88 end 88,
multiple websites have been made to assist in port triggering and port fowarding.
If all fails you may want to speak with your ISP as many have started blocking game ports during high traffic times.