rtcp-mux stands for RTCP multiplexing.

It is a process whereas RTP and RTCP share the same socket and connection, instead of using two separate connections.

This allows reducing the number of opened sockets and pinholes that need to be managed and reduces the resources required to get a session work through a firewall or NAT device.

While rtcp-mux is common in WebRTC, it is in less common use by other VoIP services and protocols that make use of RTP and RTCP.

See also BUNDLE.

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The WebRTC Glossary is an ongoing project where users can learn more about WebRTC related terms. It is maintained by Tsahi Levent-Levi of BlogGeek.me.

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