Virtualization allows for hardware consolidation, but this creates risk if all CUCM nodes reside on a single physical host.

: Minimum 1Gbps physical NICs; 10Gbps is recommended for high-density environments.

Successful deployment hinges on three pillars: selecting the correct OVA template based on device count, ensuring 100% resource reservation on the hypervisor, and implementing proper HA design using Anti-Affinity rules rather than relying on hypervisor-level fault tolerance. By adhering to these specifications, organizations can achieve a robust, scalable, and fully supported unified communications infrastructure.

: CUCM must be installed using the official Cisco-provided OVA (Open Virtual Appliance) templates, which pre-configure the virtual hardware settings. 2. Hardware Requirements (Compute & Storage)

: CUCM 12.0 and later use Cisco Smart Software Licensing. Ensure the virtual machine has a stable UUID/MAC address ; if the virtual hardware changes significantly, the license "re-host" may be triggered.

: Generally not required for CUCM, but check specific requirements if using certain packet capture or monitoring tools. 4. OVA Templates & Sizing