I am getting ready to attempt my first ever CUCM, Unity, and Presence upgrade. I am currently running 9.x and want to upgrade to 11.x. My environment is as follows: I have two UC220 servers running VMWare 5.1. I have a CUCM, Unity, and Presence server running on each for redundancy. Because I have two servers, do I need to order two "upgrade" kits or just one of each application? Do I need a single license or multiple? I'd think I'd need multiple licenses, but this is the first time I have ever done this upgrade and I am not 100% sure. I want to make sure I get what I need and nothing more. If anyone in the "community" has done this upgrade, Id like to hear any suggestions you may have or any references you may have used to help with your upgrade process.