We have legacy PRI MGCP gateways connected to our UCM (6.1.5). Our inbound calling comes in on these lines. When we place outbound calls they go out our SIP trunk. We have worked thru most all issues we have had, except for one. When we have an inbound call and do a "blind" transfer the call will fail. This is because of a G.711 to G.729 codec change. TAC suggested we add a MRGL to the SIP trunk and check "Media Termination Point Required". This works, but we do not have the hardware resources to support this for all of our outbound calling. It was then suggested to use a software MTP, which is against Cisco best practices. Has anyone else ran into this issue and what was your solution? Just as a side note, consulted transfers work just fine.
