The modders are still working hard to hammer out the funnier side of the mod and it is my understanding that when this is done there will be a permanent server running. But untill then there is a steam group
(in this thread) that you could join where we announce games.
Also joining a regiment (like
this regiment which is the modders regiment) that plays the mod works wonders for the online experience.
Tuesdays, Saturdays and Sunday evening (21PM CET) is also the best bet to find players.