They are saying that if the CUCM version is 12.0(1)SU2 then the recommended CUAC version should be 12.0(3). The supporting minimum version of the CUAC should be 11.0(2). Currently, we are in this stage.
Our plan is to go to the CUCM version 12.5(1)SU4 & the CUAC version 12.0(5). But the supporting minimum CUAC version of the CUAC is 12.0(4).
Then How we can proceed with the upgrade without losing connectivity between the CUCM and the CUAC.
- Because if we upgrade the CUCM first it will lose the connectivity with the current CUAC (11.0.2).
- If we upgrade the CUAC first it will lose the connectivity with the current CUCM (12.0(1)). Because the supporting minimum CUCM version for the CUAC version12.0(5) is 12.5(1).
So need your valuable advice here to sort this out.
Are you planning to upgrading CUCM and CUAC on a single downtime window or you are doing the upgrade in phases, means first weekend you upgrade the CUCM 12.5(1)SU4 and the CUAC to 12.0(5) in second weekend or later. If you are upgrading CUCM and CUAC on same window, i see no issues.
Actually, we cannot go to the 2nd option. Because upgrading the CUCM to 12.5(1)SU4 will lose the connectivity between CUCM and CUAC until we upgrade the CUAC at least to 12.0(4).
Here we want to verify how will be the behavior if we upgrade both in a single downtime? means it will lose the connectivity for a moment. The concern is will they connect each other automatically after upgrade to their destination versions?