Core Issue
A Media Gateway Control Protocol (MGCP)-registered T1 on a Cisco IOS voice gateway drops hard during calls. After placing about four calls, the voice T1 deregisters from the primary Cisco CallManager. Calls are lost. It then registers with the secondary Cisco CallManager. After 60 seconds, it registers again with the primary Cisco CallManager. All of the PRIs restart randomly.
Resolution
This issue is documented in Cisco bug ID CSCeh19711.
Issuing the mgcp rtrcac and mgcp voice-quality-stats commands causes this issue.
To resolve the issue, remove the commands from the MGCP gateway.
The issue arises because the commands are only for PGW 2200. They not compatible with Cisco CallManagers. There is no warning message while configuring these commands for Cisco CallManager.
