Ok so I found this thread that describes my problem perfectly. The guy even has a solution at the end. Unfortunately when I implement his solution it does not work for me. I am trying to figure out for one what is earlyRTP and how do I troubleshoot earlyRTP to figure out how to get the ringback tone working on sccp phones. The ringback works fine on internal calls and on another IAX trunk line that I have with another service. But for whatever reason it does not work on my outgoing SIP trunk line. Thank you for any help.
No Ringback on Some Outbound Calls - General Help - FreePBX Community Forums