I am looking to upgrade my phone environment from 9.1 to 11.5 and I have a couple of questions. My environment consists of 6 Virtual Cisco appliances on vmware, 2x CUCM, 2 x Presence, 2x Unity all running around the same version of 9.
1. when upgrading do I have to do them 1 appliance at a time, or can I do multiple appliances at once?
2. do i need to upgrade both CUCM appliances before I do the Presence and Unity ones?
3. when the upgrades are done I assume I will need to get my licenses upgraded by Cisco as well is that correct?
You can upgrade CUC at any point in time, the answer to your sequencing questions around CUCM and IM&P are covered in the above documentation, as well as the whole procedure, pre-reqs, post-upgrade checkst, etc.
As to licensing, yes, assuming you have your contracts in place to perform the major upgrade, you can reach out to licensing to get your 9.x licenses into 11.x licences.