Does Nokia N80 or will Nokia N80 be compatible for voip calls?

Yes and no!

The N80 support SIP but does not have any VoIP software on it as standard. There are several software companies creating VoIP software for the N80 but at the moment there isn't a stable solution.

The Nokia e-series (Eg e60, e61, e70) DOES have VoIP software installed and are compatible with the aql system. - see this page

More help available from technicians via our online support system.