Cisco Unified Communications Manager software is the call-processing component of the Cisco Unified Communications system. Cisco Unified Communications Manager extends enterprise telephony features & capabilities to packet telephony network devices such as IP phones, media processing devices, voice-over-IP (Vo IP) gateways, & multimedia applications. Additional services such as unified messaging, multimedia conferencing, collaborative contact centers, & interactive multimedia response systems are made possible through Cisco Unified Communications Manager open telephony APIs.