I am currently planning an upgrade of our cucm servers. I am going from 7.1.3 to 8.5(1) as I understand it I can go straight from 7.1.3 to 8.5. I currently have 1 pub server and 2 sub servers. From what I've read I should upgrade the PUB server 1st then start with the sub servers 1 at a time. I've checked out the hardware compatibility and everything looks good.
1. do I have to install new licenses?
2. do I have to install new locales?
3. we also have a unity server 7.0(2) will this have to be upgraded as well?
and 4 any pointers or heads up would be appreciated.