Using a FRITZBOX 7390 router
SIP provider is Sipgate.
Cannot call from Zoiper to an internal extension
Dialing **610 (internal number) return error 404.
These internal numbers are assigned by the router.
Normal outgoing numbers are OK.
You may need to remove the * sign from the Strip dial characters in the Number rewriting section from the account configuration.
No signs exists in that section.
List is empty.
in that case it is possible that the PBX is stripping the characters. You will need to check with your VoIP provider.
Thanks Ivan.
Unfortunately it is not a provider problem.
Normal DECT phone does not have the problem.
I can even call internaly from a phone to zoiper.
Not the other way though.
It exists only in Zoiper.