I believe this issue is rellated to the SR :http://wwwin-tools.cisco.com/casekwery/getServiceRequest.do?id=615699607 which was handled by me.
where, we have diagonized that,
when the media is setup for the recording call,e.g. the call from BIB to the recorder, the media is asking for the MTP but MTP is not available. Then the recording call was torn down and that's why BYE was sent to the recorder over the sip trunk.
You said, you would open a TAC case to assist you on setting up the MTP, do you need any help on opening the TAC case?
My search has got to this page which states about 'Media Resources: Media Termination Point Parameters'
We are having a similar problem. SIP Trunk and MTP have been checked and they work fine when an external call goes directly to a phone; MTP resources are allocated correctly. If we try to transfer the call from the phone to CUAE, it fails and the call is disconnected.
When the call goes to CUAE instead a phone, no MTP resources are allocated but the script seems to work fine; MTP is requiered but not allocated. It seems like CUAE is working like MTP. If we try to transfer the call from CUAE to a phone, it fails and the call is disconnected.
Thanks & Regards,