I'm running CUCM 126.96.36.19900-11 in VMWare Workstation for my lab, Demo License. I want to use 8851 phones so will need to add the Dev Pack 9.1(2.16147) so they appear as an option to add a phone. Will I need to upgrade the cluster to 9.1.2 in order install the dev pack? Or, can I install the dev pack to the existing 9.1.1 version?
you need to do minor upgrade to 9.1.2
You are most correct! You can't install a 9.1.2 device pack on a 9.1.1 CUCM so you would need to upgrade to at least 9.1.2. If you upgraded to the latest 9.1.2 version support for the 8851's would be included already.
EDIT: +5 to my buddy Aman for his good tips and for his superior typing skills!
It will work with demo licence, but when demo licence expires you would need Enhanced license.
(Rate if it helps)
IP phone would work with demo licenses for grace period of 60 days.
After the expiry of same, u need to purchase permanent licenses.