Out of curiosity, where are you located in the world?
Battlefront does some process in the background where it pings servers, and only allows you to join games running on servers that it deems acceptable.
If your internet latency (ping) is too high, or you are in a remote location far away from a server, you won't be able to play very well.
I'm in south africa and during quiet days I can't join any games either.
No port forwarding should be required (Port forwarding is for inbound connections, you don't have to port forward based on the inherent nature of dedicated servers and how you connect to them.)
Please visit www.speedtest.net and allow it to run a speedtest to the nearest capital city of an EA country (or if you know where the servers are located.)
I've seen plenty of games do this where they wont let you matchmake on a server if your ping to that server is above a pre-set limit. This is done to avoid people connecting to international servers and giving people a poor gameplay experience.
(personally I think not playing at all is a worse experience.)
Stats from http://swbstats.com/