I'm trying to link our 3CX installation to an unsupported SIP provider (Zadarma). I would like to use a single trunk for multiple incoming numbers, and I can see in their Invite messages that there is a header "CALLED_DID" which contains the number - however the To: field contains their extension number I'm connecting to.
I can't figure out if there's a combination of settings in the Inbound Parameters page which will let me take the value from a custom header and use it as the CalledNum param, so that I can then assign all the numbers we have and manage them solely in 3CX with Inbound Rules.
The only place on Inbound Parameters where I can specify a custom header is in the bottom field under Call Source Identification and I don't think this is the right place. Any suggestions or indications whether what I want is possible to achieve?
I can't figure out if there's a combination of settings in the Inbound Parameters page which will let me take the value from a custom header and use it as the CalledNum param, so that I can then assign all the numbers we have and manage them solely in 3CX with Inbound Rules.
The only place on Inbound Parameters where I can specify a custom header is in the bottom field under Call Source Identification and I don't think this is the right place. Any suggestions or indications whether what I want is possible to achieve?
