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!
@Krieggs You can give this a read: https://forum.faforever.com/topic/2264/moved-to-australia-is-it-still-possible-to-play/7
I get asked this question about the inner workings of the ice adapter quite a lot, I think I should write that down in the Wiki in more detail.
