Mixing is an architecture for multipoint where every participant sends its media to a central server and receives the single media stream from that server that mixes all (or some) of the streams it receives.
The mixing server is called MCU.
Advantages of mixing architecture
- Requires little effort from the client to support this, as for the client this is a regular P2P session
Disadvantages of mixing architecture
- The most expensive of the options, since the MCU needs to decode, layout and re-encode the media it receives for all participants
Other multipoint architectures are mesh and routing.