We're currently running the below UC applications and I'm trying to determine the best order for migration:
CUAC Enterprise 9.1.1
Does the Attendant Console have to be migrated first? Is anyone running the CUAC 9.x in a 10.x environment? If possible we would like to hold off on upgrading that component until later, but not sure if it's possible.
CUC is pretty much a wildcard, you can upgrade it at anytime and still keep CUCM compatibility.
Yes, no AC on 9.x is compatible with 10.x CUCM, but 10.X ACs are compatible with 9.x CUCM.
It would be AC -> CUCM -> CUC