Hi,
I have a UCMBE 7.1 and as of about a month ago, the CallManager Service began stopping and restarting, every couple of days (18 hours- 3+ days).This is a signle CM site, so when this happens IP Phones drop out and re-register when CM comes back online. I've identified that the CM service is stopping and restarting using the RTMT tool, other then that, I don't know how to further diagnose the problem.