I want to use Openser to register all phones.
If the phone is allowed (paid) than it should be able to reach a certain
gateway (flat rate to certain numbers)
Distinguished via mysql database.
If the destination number is not in the flat rate, than the call should
be forwarded to Astersik to handle the call (prepaid card)
If features are requested, than should be also Asterisk handle it.
Is there a starting point for this set-up?