When user tries to transfer an answered call to a RDP enabled directory number, he is unable to transfer the call.
Customer dials User A - User A answers - User A dials User B- User B has enabled RDP to his mobile number - User B answers in mobile phone - Customer is on hold - User A tries to transfer the call to User B - call to User B drops out - Only Customer and user A stays connected.
MTP isn't checked, which I confirmed. The call flow is ITSP > SIP > CUBE > SIP > CUCM - extn A > Answers > A Dials extn B > RDP > Mobile > CUCM > SIP > CUBE > ITSP> Call answered by B > A tries to transfer the call to B > Call fails > B disconnected.
When I checked the failed called logs I could see the remote device (Mobile) is sending cancel message followed by 487 request cancelled by CUCM and Bye. Anything I should verify before I enable MTP in sip trunk?