What is the best way to determine the date that a particular ip phone last registered? For example, say there are several old CIPC objects configured in CUCM Devices>>Phone that we need to clean up to reclaim the licenses. I'd expect if we could determine that any of them were not used in a few weeks, that they were no longer active and could be removed. I'd rather not take the crude but effective approach of breaking the connection and see who notices. The version is CUCM 18.104.22.16800-2.