Change internal Caller ID

Hello

I have FreePBX 13.0.192.19 with Asterisk Version 13.17.1 running on a Raspberry Pi 3

I am trying to set up a test station to test and program analog emergency phones (Code Blue ia4100). The phones are programmed to dial a number when the help button is pressed. If no one answers, it hangs up and then dials the next number and so on.

I need the pbx to forward the call to another phone and I need the called phone to display on the Caller ID the number that was dialed from the emergency phone.

I have the emergency phone attached to a Cisco SPA112 ATA Extension 701 and the phone that rings is a Grandstream GXP1620 Extension 703. I have set up ring groups for the numbers that I want to be dialed (example 1160) and have them set to ring extension 703.

The system is working and forwarding calls as expected but I would like the Caller ID to show the extension number of the ring group that was dialed (example 1160) instead of the extension that the call originated from (701).

I have tried setting Change External CID Configuration in the ring group to Fixed CID Value but it doesn’t seem to work with internal extension to extension calls. CID Name Prefix does work and I use it to give me the description of the Extension that is being dialed, but I would really like to have the CID number changed as well.

BTW, I am new to Asterisk and FreePBX

Thanks in advance

If anyone else needs to know, I figured it out. I set up a loopback trunk and then set an outbound route to use the loopback trunk if the dialed number matches 3698. I set my ring group to ring 3698# and set the Fixed CID Value to match the ring group extension number. I then set an inbound route to match the Caller ID for each ring group and selected CID Priority Route. I used the CID name prefix to insert the CID Name. It would be nice if I could find a more efficient way to do this, as I have a lot of ring groups to edit and inbound routes to create, but I’m happy to have it working