I am preparing to migrate users from a CCM 3 to CUCM 6 Cluster using a site-by-site migration as opposed to a big bang.
The Customer also has Unity Unified Messaging and a new pair of Unity 5 Servers is to be integrated with the new CUCM 6 cluster and AD. My intention is to migrate all users off a legacy Unity 4 server integrated with AD and the CCM 3 Cluster before any user migrates across to the CUCM 6 platform - i.e. they will be registered to CCM 3 but using Unity on the CUCM 6 cluster.
Both CCM 3 & CUCM 6 Clusters are connected by ICT to support the migration strategy. All manipulation of call routing will be made to support the site migrations via the ICT.
What I am not sure about is when a User on the CCM 3 cluster sends calls to Unity 5 (on the CUCM 6 Cluster) by having CFNA, CFB etc set-up, does RDNIS information get propogated across the ICT so that the caller gets presented to the correct voicemail box ?
Also, when a User hits the Messages key on his phone connected to CCM 3 and the call is routed across the ICT, will RDNIS be presented so that the user hits their Mailbox and not the standard Unity greeting ?
Anyone done this migration strategy before ?