How to differentiate between internal and external call handling

[VSC]

I'd like to handle an internal incomming call different than an external incomming call. An internal caller should be able to reach a specific extention whereas an external caller is redirected to an IVR announcement.

How can I achive this?

 

[Saqqara]

For external calls, you configure your trunk / sip to forward to the configured ivr

for sip - calls to this number can be processed by an inbound rule in “SIP trunk” > “General” tab > “Route calls to” section.

more info here - https://www.3cx.com/3cxacademy/videos/basic/configuring-voip-providers/

 

[leejor]

I'd like to handle an internal incomming call different than an external incomming call. An internal caller should be able to reach a specific extention whereas an external caller is redirected to an IVR announcement.

There is really no such thing as an "internal incoming" call, as the call does not come into 3CX via a trunk group, with the possible exception of calls over a Bridge trunk.
This is the way it normally works. An external caller (trunk group) can be routed to an IVR, you choose where their calls goes. An internal caller would have to dial the IVR number to reach it, just as they can dial another extension, by default.