MCU Multipoint Control Unit
MCU is an optional component of an H.323enabled network that controls conferences between 3 or more terminals. It consists of:•
A mandatory Multipoint Controller (MC) used for call signaling and conference control.
An optional Multipoint Processor (MP) used switching/mixing of media stream, and sometimes realtime transcoding of the received audio/video streams
Although the MCU is a separate logical unit, it may be combined into a terminal, gateway or gatekeeper.
The MCU is required in a centralized multipoint conference where each terminal establishes a point to point connection with the MCU. The MCU determines the capabilities of each terminal and sends each a mixed media stream. In the decentralized model of multipoint conferencing, a MC ensures communication compatibility but the media streams are multicast and the mixing is performed at each terminal.