A week or so ago I was working on a Multicast MOH problem and I read a post in which a user said that the way to get it to work was to enable require Media Termination Point. Not only was this not required but it also had calamitous effects to my voice service.
My problems didn't manifest for a few days. However when they did the problems became severe. A few days after making this change I started to experience severe degradations in voice quality. Not only that but my Full T-1 Frame Circuit was seeing 80% utilization(our voice PRI resides locally this should not ostensibly be affected by high WAN utilization too much.
After about 6 hours with TAC we finally discovered the problem. It would appear that when you check off require MTP on a gateway that means that the Call Manager gets involved in EVERY RTP session. So each call would need to go over the WAN to the CM and then back to the IP Phone. This caused severe problems at the branch AND with the Call Manager which was seeing very high utilizations since it was decoding and re-encoding each call.
The moral of this story is twofold. 1) Don't check off the require MTP button in the configuration without a darned good reason and 2) Just becuase someone on these message board says that what they did fixes the problem doesn't mean they are correct AND you should ALWAYS read up on what you are planning on doing before you do it, something I know very well but sometimes forget.
