CUCM 15 was released in December 2023 with 15.1.X being released later this quarter of 2024. Cisco have made significant hardware changes which may surprise many and potentially make it difficult to directly upgrade from 12.5 or even 14.X. Any CSR versions Pre-12.5 will be even more difficult.
We have done our best to outline these changes given the limited time this release has been out. This is the by far the biggest change we have seen in the last 15 years since CUCM 4.X, a Windows based install moved to CUCM 5.X a Linux Redhat install.
In this article, we have summarised some of the required hardware specs, interesting features, and the best approach to tackling this upgrade.