CUCM LDAP configuration w/ Multiple Domains

[mumbles202]

In a CUCM 12.5 environment is it possible to do a migration of a system from 1 domain to another and transition rather than replace?  As in userids are AD integrated in domain_x; the same users exist in domain_y.  Is it possible to to have both users appear in CUCM while transitioning or would it be better to try to export all the users, delete them from CUCM and then replace/update using BAT?

[Roger Kallberg]

With AD synchronisation the user in CM uses the PKID of the user account in AD to track the user. As this would not be the same in the other AD domain, even if the name of the account is the same, it would be another user account if you where able to synchronise CM with dual domains, which you cannot as CM only supports synchronisation with one domain.

[mumbles202]

Thank you.  Is there a good solution to go from one domain to the other?  

[b.winter]

What you are probably looking for is "Multi-Forest AD for CUCM":
https://myitblog.co.uk/cisco/cucm-integration-in-a-multi-forest-environment/

https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-version-80/111979-ucm-multi-forest-00.html

[Roger Kallberg]

It’s pretty much a rip and replace kind of thing. You’ll need to come up with a plan for how to get the current users and its assignment and then reassign this once you’ll have the new users in place. As this is a definite user facing impacting activity I would strongly recommend you to do this during a defined service window. Also a solid back-out plan would be advisable.