Unified CMBE 6000 supports full feature redundancy. You can configure hardware redundancy for all the applications by deploying a secondary UCS C200 server and turning on high availability feature supported by each one of the applications. If a customer is migrating from MCS based Unified CMBE 5000 or Unified CM and would like to configure redundancy only for call processing they can do so by configuring the instance of Unified CM running on the MCS78XX as a secondary/subscriber node.
http://docwiki.cisco.com/wiki/Cisco_Unified_Communications_Manager_Business_Edition_6000
