I have a three server CUCM deployment running 6.1.1. I am upgrading to 6.1.3.
I currently have 6.1.3 installed on all three servers' inactive partitioin.
I understand I need to reboot the pub in the new version, wait 10 minutes or so, then do same procedure for sub 1 then sub 2.
My question is will I experience any downtime during this other than phones re-registering between servers?