Not quite, let me explain it better:
All users dial 0 for an outside line.
Office A is in NSW. The area code for NSW is 02.
Office B is in QLD. The area code for QLD is 07.
When a user in NSW wants to dial a QLD external number, they know very well they have to dial 0 07 +8 digits.
When a user in QLD wants to dial a NSW external number, they know very well they have to dial 0 02 +8 digits.
When a user in NSW wants to dial a NSW external number, they dial 0 +8 digits.
When a user in QLD wants to dial a QLD external number, they dial 0 +8 digits
(If I have a controller in each office, it's easy - I use ARS digits on each controller to send 0 +8 digits out the local PSTN.)
But if my controller is in the cloud, how do I know that
0 +8 digits from a NSW user means 0 02 +8 digits to the PSTN
0 +8 digits from a QLD user means 0 07 +8 digits to the PSTN
Somebody told me how to do this but I completely forgot.