Release 9.0(1) provides a tighter integration between IM and Presence and Cisco Unified Communications Manager (Unified CM). From Release 9.0(1) onwards, IM and Presence and Unified CM software versions must match. For two software versions to match, they must have the same major and minor release number. Major and minor release numbers are defined as follows:
where 9 = major release number, x = minor release number and y = maintenance release number.
For example, IM and Presence Release 126.96.36.19900-1 is compatible with Unified CM Release 188.8.131.52000-3, but it is not compatible with Unified CM Release 184.108.40.20600-5. Similarly, Unified CM Release 220.127.116.1100-6 is not compatible with IM and Presence Release 18.104.22.16800-1.
For fresh installations, Unified CM 9.0(1) must be installed before IM and Presence 9.0(1) is installed. For upgrades, Unified CM must be upgraded to Release 9.0(1) before IM and Presence is upgraded. Upgrades must be performed within the same maintenance window.