Issues With External Callers calling into a CTI that Routes to External Number

[hargues45]

I have a particular scenario that is less than ideal. Basically a user dials a DID we own, its handed to our SIP Gateway and the handed to CUCM where it gets sent to a CTI route point that then forwards to an external number.However there is no ringback from either the CTI or the external number but if I call internal to the CTI i do get ringback. I have identified the traces and i do not see SDP 180 messages coming through, which I believe may be by design. I have listed the traces below from the particular call. Thank you in advanced for any help!

[KT4RJN]

Your 180 RINGING message is not being sent from the CUBE.
I found this helpful to explain it:

https://community.cisco.com/t5/ip-telephony-and-phones/difference-between-180-ringing-and-183-session-progress/td-p/2413632

In a similar discussion, they mention a workaround to disable early media. Is your CUCM sending 180 ringing back to the CUBE?

https://community.cisco.com/t5/ip-telephony-and-phones/cube-converting-sip-180-ringing-to-183-session-in-progress/td-p/2010478

[hargues45]

Thank you very much for the response, Jonathan! Unfortunately it is not. It appears that the 180 ringing with SDP maybe getting converted to 183.