Videoconference

MCUs (Multipoint Control Unit) are star distributors for group conferences with more than six participants or high bandwidths. The MCU is linked with all participants. It manages/regulates the incoming and outgoing video and audio data streams. The MCU does not negotiate with the connected end devices via the bandwidth. This is specified by the MCU. The incoming audio data streams are only mixed in the MCU and are sent back in full-duplex mode. The video data streams are processed in two ways:

Continuous Presence: A new video data stream is generated from the incoming video data streams and is sent back to all participants.

Voice Switching: When the MCU presents the video conference in Voice Switching mode, all conference participants can see only the participant speaking at the moment.

Gatekeeper
A Gatekeeper is a central control unit for routing call signal, the resolution of telephone numbers and the IP address and its conversion.

Gateway
A Gateway produces the transition and the link from the IP network to the ISDN telephone network.