This alert indicates that the CallManager process is not generating and/or responding to heartbeat requests in a timely manner. If the heartbeat rate slows down significantly, this indicates a problem with the Cisco CallManager service; the service might be going down. Here are some of the reason why:
- High CPU utilization
- BARS
- Antivirus maybe updating
- Could be CDR
Please check your Event Viewer for more errors.
HTH