I have a customer who is migrating their users to a new domain within their AD infrastrucutre. They are using a migration tool so that the users will retain their SID. They currently have UCM, Unity Connection, and Presence, all tied to the existing AD. Question is what needs to be done these applications to accomodate for the users in the new domain? Is it a matter of creating/importing new users after pointing to the new domain?
As for Unity Connection, if you hav version 8.x, you'll want to follow the steps in this article to temporarily convert your existing users to remove their LDAP integration status. Then, set up the new LDAP agreement with the new domain, and convert them again.
I'm not sure about CUCM, so you might want to post this same question in the IP Telephony section. https://supportforums.cisco.com/community/netpro/collaboration-voice-video/ip-telephony
We are looking to achieve (I think) what you were looking to set out about 5 years ago migrating our UC applications from one domain to another. If you wouldn't mind sharing, what was your process?