CUCM 12.5 releases follow this naming pattern:
October 26, 2023 Subject: Acquisition and Update Status for Cisco CUCM 12.5 cisco cucm 125 download updated
Learn about the transition from 12.5 to the latest Release 15 in the Upgrade Planning Guide Find critical security patch details and bug fixes in the ReadMe for Release 12.5(1)SU9 Compatibility Matrix CUCM 12
Cisco Unified Communications Manager (CUCM) 12.5: Official Download and Upgrade Guide and presence. Same software portal
Cisco Unified Communications Manager (CUCM) is a software-based call processing system that provides a comprehensive set of features and applications for enterprise-level communication. It is designed to manage and route voice and video calls, as well as provide advanced features such as unified messaging, conferencing, and presence.
Same software portal, but filter by “COP” or “Device Pack.” Install COP files after installing the base ISO but before adding devices.