[cisco-voip] UCM Upgrade

[Jeff Mottishaw]

We have a Call Manager cluster (pub + sub) that is horribly out of
date (6.0.1.2000-3). We have intentionally avoiding updating because
our phone users are all billable resources and some do not deal with
change very well. Since we have no idea how our complex config will
look on the new versions we can't come up with a training manual, etc
etc. We are now running into a couple bugs (Extension Mobility and
Call Parking) that are fixed in newer versions.

I'm writing to ask how you all deal with testing updates. I initially
looked at running a CallManager lab in VMware to give our admin staff
a chance to try (manually change the TFTP server on their phones) the
update before we rolled it out to the production server but the
licensing limitations have temporarily killed that idea.

If we roll out the upgrade on a Friday, have our admin staff come in
on Saturday to test can we safely roll back to the previous version
(backup partition) on Sunday provided we don't make any changes to the
configuration?

Thanks in advance for your help and feedback.

Jeff