call manager migration version 9.1.2SU2 to 12.5.1SU2

[ragz3000]

I have 2 call managers 9.1.2SU2  in a cluster on Cisco UCS servers and want to migrate them to 12.5.1SU2 on a VMWare infrastructure (non-cisco hardware). Cisco document mentioned RU upgrade or PCD migration. If I want to decrease the downtime, what are the options?

I also want to build a new CUC server with 12.5.1SU2, as this is not compatible with existing cucm v9, is my only option to wait until cucm migration is completed? Appreciate some assistance if anyone has come across this situation.

[Nithin Eluvathingal · Accepted solution]

PCD migration will be your best option.

its better to follow the guides, so wait till you migrate your CUCM cluster. or if you want to have try, use SIP integration.