Issues transferring call to external number using CUCM/CCX (no audio)

[bix99]

Hi folks, hoping I can get some advice on troubleshooting steps for a calling issue I am having. TAC has been assisting for 3 months but has been no luck as yet, so running out of ideas.

Environment CUCM 12.5 SU6, CCX 12.5, CUBE (router 4451 with 17.12.x software).

Scenario: We have external customers call our main inbound number, this hits CUCM and then into CCX to perform a time of day workflow, which will then send the call to a translation pattern which points to an external phone number which is a 3rd party IVR/call centre. when the call transfers to them, it has no audio both ways, the call just seems blank. 

It has been working for years but stopped a few months ago (im unaware of any specific changes which would have affected this setup).

Call Flow: Pstn >> CUBE >> CUCM >> main number >> CTI >> CC >> transfer to external number >> CUBE >> pstn

I can call the external number from my ip desk phone fine. I can transfer my deskphone to the external number and call from my cell to ip deskphone and it will transfer to the external number fine. It just seems to encounter this no audio issue whenever the calls go via the entire CCX workflow.

I have pulled logs from CUCM and ran various commands on the Cube while call is active but none of this has seemed to help TAC pinpoint the issue. have engaged the SIP provider who hasn't been much help identifying any issues. 

Open to any suggestions on testing or config adjustments which may help pin point the problem? I have various CUCM logs of the issue. 

[Jerrytech1]

Try routing the calls through Unity/Call Handler. You can duplicate the time of day using the schedule in Unity.

[Elliot Dierksen]

There is ToD routing in CUCM, but I do find it a little clunky. Is it possible that the codec re-negotiation is getting messed up when the call gets transferred back out of CCX? You could use RTMT to download the call logs. Translator-X can look at those logs and give you a better view of it. Is it every call, or just some calls?

[bix99]

Yes - every call affected when using the CUCM/CCX workflow. 

I do have logs from RTMT and translatorX but fumbling my way through what all the entries mean. 

[Elliot Dierksen]

I would suggest you try forcing an MTP on either the CTI route point that handles the call or CTI ports (call control group) that are used for this application.