SIP behavior differs --- internal vs external calls

General Help
1

When a call is not answered by a Freepbx extension the call is sent via sip to an external voicemail program.

Analyzing the SIP call via wireshark.

If the call originated from an external source the call no answer behavior is

Invite [email protected]. <-----this is the desired result and it works properly.

If the call originated from an internal source (another freepbx extention) the call no answer behavior is

Invite 172.16.16.1 <------this is not the desired result. It is missing the Sip extension.

Can anyone tell me where to check the SIP behavior of a call? The external behavior is fine, but internally it doesn’t prepend the sip extension to the invite to the external voicemail program.

2

I am seeing this same issue when I run a Wireshark.

I am guessing that in order to fix this one is to modify the dialing / call flow script. The FreePBX scripting I am still trying to figure out which file I would need to edit to modify this packet header information.

Can anyone provide some assistance on this one?