The actual product is Cisco Unified Communications Manager (CUCM) for call control and Cisco Unity Connection (CUC) for auto attendants and voicemail.
The Business Edition appliances are just pre-packaged x86 servers with prescribed virtual machine specs for a given scale. They were created to make a traditional telephony buyer persona less intimidated of virtualization. If you’re comfortable with VMware, ignore the BE appliances and just deploy the Cisco-provided OVAs (required to be supported) and then install from a bootable ISO. If you’re going to run this in production and expect Cisco to support it, be sure it follows all the virtualization requirements and documentation. The ISO bit is going to be tricky though. AFAIK the only way to get a bootable ISO is with a paid subscription for CUCM/CUC. The actual product will run unlicensed for 90 days if you can get ahold of the ISO though.
Fair warning: CUCM is a really mature product with a lot of nerd nobs to address various customer use cases over the last 25+ years. It was built to run everything from a small 100 user company to the largest global installs in the world - commercial and classified. It’s all in the same GUI, there isn’t a simplified starter toggle. It has, no joke, thousands of pages of documentation. This can be intimidating to learn on your own from scratch. The vast majority of new deployments these days are a simpler to learn UCaaS solutions such as Webex Calling. Not trying to scare you off. Just be clear what your objective is.
