Cisco TelePresence Video Communication Server Control (Cisco VCS Control) provides advanced telepresence applications and session management to all standards-compliant telepresence endpoints, infrastructure, and management solutions. Cisco VCS Control provides Session Initiation Protocol (SIP) proxy and H.323 gatekeeper services, enabling any-to-any interoperability between SIP and H.323 telepresence devices. Cisco VCS Control is a critical part of Cisco's unified call-control solution and is also critical for interoperability with third-party unified communications and IP telephony networks and voice-over-IP (VoIP) solutions.