The current pre-release of the client ("pioneer" in the version) is only compatible to itself. So you can only play with other testers. Please be aware!
If that is the case, then FAF is almost certainly leaking sockets. My system only has ~200 TCP sockets open at idle, and only ~10 of those are in active use at any given time.
I wrote a little script to monitor it and log the TCP port count and activity. Hopefully my next game will reveal the issue.