Distinguish outbound calls from calls between extensions
Use ARS to distinguish outbound calls from calls between extensions.
It is possible to use the prefix number for outbound calls.
For example, you can use 9 for dialing prefix.
To = sip:9(.*)@
Also it is possible to create a matching rule with the number of dialing digits.
Usually, local PSTN number is 7 digits or more.
To = sip:([0-9]{7,})@