I have 2 branch offices in different cities. Each office has its Asterisk server installed locally. I am trying to let user A at city A (Asterisk box A) be able to call user B in city B (Asterisk box B) through VoIP not through the landline. The “sip_additional.conf” and “extensions.conf” both are NOT centralized either.
Can someone give me a direction on how this could be achieved? I think this is something like “Asterisk- relay” or “corss - Asterisk” call something.
Many thanks for your help in advance