I have a strange problem with Cisco IP Communicators go unregistered from CallManager at 03:15 in the morning. It's intermittent, ie. not every CIPC will go unregistered but usually most will, and it's always at 03:15. This causes us an issue because the CIPC are used by our UCCE agents to take calls, so the CIPC unregistering causes them to be logged out. They can log back in OK once they have re-registered so it not a disaster, but a nuisance. At first I thought it may be an issue with CallManager (v6.1.2.1001-4) but soon realised that the only phones going unregistered were CIPC's, never desk phones and the CUCM event viewer log files first show "%CCM_CALLMANAGER-CALLMANAGER-6-StationConnectionError: Station device closing connection", followed by a device unregistered with reason code of 8 (Device Inititated reset) It also made no difference to which of the six subscribers in the cluster the CIPC's were registered to. I then registered a couple of the CIPC's to our 7.1.3 cluster (which normally does not have CIPC's connected) and those two CIPC's phones still went unregistered at 03:15, effectively ruling out the CallManagers Next I considered network issues, but the CIPC's involved (approx 30) are based in different buildings, therefore different subnets, switches, routes back to CUCM servers etc. Sniffer traces showed nothing odd, apart from the CIPC's unregistering at 03:15 I considered some sort of issue on the individual pc's but there's nothing in the pc's event viewer happening at 03:15, or no known routine schedule to occur at that time. I've tried upgrading one of the CIPC's from v2.1 to 7.0.2, and no un-registration events for two weeks, so looks like it could be an CIPC issue. Before I go to the trouble of getting approval for the 7.0.2 upgrade to all pc's running CIPC, I was wondering if anyone else has come across a similar issue? Thanks Kelvin ... View more