Cisco Unified Communications Manager (CUCM), formerly Cisco Unified CallManager and Cisco CallManager (CCM), is a software based IP call agent platform sold by Cisco Systems. Cisco renamed the product to Unified Communications Manager. Version 6 was supposed to merge all features of the Linux appliance (SIP support and licensing requirements) between the Linux platform and Windows version. The released version of Unified Communications Manager will not support the Windows platform.
This version added an intercom feature between endpoints, and integrated Mobility Manager (single number reach to multiple destinations, IP Phone, Cell Phone, etc).