MCU

(1) (MicroController Unit) A computer on a single chip. See microcontroller.

(2) (Multipoint Control Unit) A device that is used to moderate a videoconference of three or more end points (users at computers or groups of users in one room). In "voice switch" mode, it determines who is the predominant speaker and automatically switches the video of that person to all the screens. In "continuous presence" mode, it splits the screens and sends the video from each site to every screen. In "chair mode," someone can manually control who is on screen at any given time. An MCU also provides an audio bridge that mixes the audio from all the end points.

An MCU may include a built-in H.323 gatekeeper for translating user names into IP addresses, a video PBX for call switching, forwarding and transfer as well as video network management for quality of service (QoS), bandwidth management and accounting. See videoconferencing.

An MCU Plus

VCON provides a complete video management and control solution with its VCB 2000 MCU. It is H.323 and SIP compatible and includes an H.323 gatekeeper, a video PBX, video network management and full streaming capabilities. It also comes with H.323 video client software for desktop PCs. (Image courtesy of VCON, Inc., www.vcon.com)