To download a Cisco Unified Communications Manager (CUCM) 12.5 bootable ISO, you must typically have a valid Cisco Service Contract or a recent product purchase. Unlike upgrade patches, bootable ISOs are considered full installation media and are restricted to specific delivery channels. Where to Find the CUCM 12.5 Bootable ISO
Alternative Method: Cisco Customer Support Portal cucm 12.5 bootable iso download
(Replace /dev/sdX with your actual USB device—be extremely careful.) To download a Cisco Unified Communications Manager (CUCM)
If you do not have a service contract and need CUCM for learning or lab purposes: Cisco DevNet Sandbox : Cisco offers free, cloud-based lab environments via Cisco DevNet ~$200/year Includes CUCM 12
Map your newly created bootable ISO to the VM's CD/DVD drive. BIOS Boot Order: You may need to force the VM into BIOS to ensure the is the first boot device. Configuration Wizard: Follow the prompts to set your Network Settings (IP, Hostname), NTP Server Security Password Cisco Community Note on Licensing: CUCM 12.5 uses Cisco Smart Licensing