The CUC cluster is integrated into the SME cluster, not the CUCM.
My problem is simple. The CUCM cluster transfers an on-net call to a CUC Call Handler (via the SME), which then transfers it back to the CUCM cluster to a hunt pilot. However, when the call is alerting the HP, there is no ring back, just silence. If the call is answered in the HP, two-way audio established as normal. Interestingly, if the transfer on the call handler is set to supervise, I don’t get music either, just silence.
I am aware that you use an annunciator media resource on the CUCM to play ring back. However, I am not sure whether it should be the SME or the CUCM cluster that should provide this facility? Initially, the CUCM cluster had media resources configured with Annunciator but not the SME, in fact the IPVMS service was deactivated on the SME cluster. As a test for the purpose of this fault, I enabled it and created an Annunciator MRG assigned to both the CUC SIP trunk and the SIP trunk to the CUCM cluster. However, the problem still exists. Note the SIP trunks between the CUCM and SME are the best practice of Early Offer.
At this point I am trying to understand which CUCM cluster should be providing the media resource for the ring back Annunciator?
If anyone has any tips or experience of this problem, it would be gratefully received.
Tim - we are seeing the same issue and pinged our Cisco account team. He came back with the following, however we haven't implemented yet.
"On the SME trunks to CUC and Leaf cluster - do you have REFER passthrough enabled? If REFER passthrough is enabled, it would use the resources from the Leaf cluster, if not it would use it from the SME cluster."