Would appreciate your advice.
We currently run CUCM 7 in parallel with a PABX system. Calls come in over H323 gateways and if the number doesnt exist in Cisco land, the call is forwarded to the PABX.
We are looking to migrate to CUCM 9 for the purpose of simplifying config and removing unused accounts. ie. Build the 9 cluster and move users over from cucm7 in stages.
The problem is, how do you have some users in CUCM9, some in CUCM7 and some in PABX all at the same time? The dial plan is all over the place - ie there is no logical separation of users with regards to their assigned extensions.