In voice and video conferencing, the MCU serves as a central hub that connects multiple participants into a single session. It can operate in two modes: mixing, where it combines audio and video streams into a single output per participant, and switching, where it selectively forwards active speaker streams to participants. MCUs are widely used in enterprise VoIP solutions, virtual meetings, webinars, and telepresence environments. They support various codecs and ensure synchronization, echo control, and layout management.
While traditional MCUs were hardware-based and costly, modern versions are software-driven, scalable, and often hosted in the cloud. They interact with endpoints using signaling protocols like SIP or H.323 and media transport protocols like RTP. For large-scale deployments, MCUs must handle hundreds of concurrent users while maintaining low latency and high quality of service.
With the rise of WebRTC and SFUs (Selective Forwarding Units), MCU (Media Control Unit) usage is evolving, but it remains essential in scenarios requiring centralized control, advanced mixing, or integration with legacy systems.
