We are planning to switch versions of CUCM from 6.1(2) to 6.1(4a)SU2 as an interim upgrade to v7.1(3). The 6.1(4a)SU2 files have been loaded into the inactive partition on all three CUCMs in cluster - all that is left to do is switch versions (PUB first, then two subs. I am just looking to see if there are any gotchas in this upgrade. The 6.1(2) OS doc doesn't go into great detail about the process other than do PUB first and then SUBS - if anybody has any input or info on things to look out for it would be appreaciated - also any idea on the time needed for a 3 CUCM cluster - we are scheduling a late night window to avoid user impact
Thanks in advance!