That's actually bloody great news! Bloody because we poured quite some effort in making the alternate mechanism happen
Anyway, I found out the issue. It seems that instead of registering the public available IP for a given server, I would register in it's local IP. No wonder only I could connect to the server I registered but nobosy else could

So, even though this might not be needed, but only to confirm my supposition, try again to join the "Aliens vs. Predator 2" server on top.
Regarding the remaining issues:
- the server is deleted from the database as soon as its innactive time (no update) exceeds a certain limit. We had a UDP based mechanism to trigger the update, but it seems we can't use all the tricks we planned for.
- the refresh of the list of servers in the database is thus performed each time one of the servers in the list makes an update: a player joining or leaving, a server changing the map, that kind of stuff.
Obviously, with only 1 or 2 servers registered, that doesn't work as well as it would work with 20 - 100 servers registered, some of them beingactive

So, regarding the IP address findings I mentioned above, if one of you guys would try to join a server using our work, I'd be grateful.
The bug was found: " Anyway, I found out the issue. It seems that instead of registering the public available IP for a given server, I would register in it's local IP. No wonder only I could connect to the server I registered but nobosy else could