I'm running CUCM 18.104.22.16800-11 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!