New by ekiga and having problems to get a connection

Hi, I have just Installed ekiga over SuSE's YAST, and I've subscribed 
for a free ekiga.net account. Ekiga will process for some time and then 
just stop saying server unreachable. I am hanging on a firewall/router 
zxv10 from the telephone company, and otherwise I'm using SuSE 13.2 with 
it's firewall unchanged...everything should be open in the router (says 
the telephone company technician) and I know my SuSE firewall is open, 
at least on the way out.

Where can I change what, so that ekiga will work?

Thanks in advance,
Alejandro Frasch