CMS HA provides redundancy to reduce the potential loss of call center data. You can configure HA if you have two CMS servers, which are typically installed in separate data centers. Both CMS servers must operate on the same release and maintain a similar capacity. HA configurations designate one server as the primary and the other as the secondary. When the primary CMS server goes down, the secondary CMS server takes over. CMS servers connect to an Automatic Call Distribution (ACD) system. CMS supports the Automatic Call Distribution (ACD) feature of the Avaya Aura® Communication Manager system.

You can optionally configure a dual-IP primary or secondary CMS server. The dual-IP option enables the assignment of two IP addresses: One connects to the main ACD, for example, Communication Manager, and the other connects to an Enterprise Survivability Server (ESS) Communication Manager system. During a standard operation, the dual-IP CMS server collects data from the main ACD. When a fragmentation or failure occurs, the dual-IP CMS server collects data from ESS Communication Manager.