There are many prior articles on the web about the WebRTC media path topology in a multiparty scenario. Those usually cover the basic topology of full-mesh and centralized, including MCU and SFU.
In practice, conferencing systems often exhibit complex topologies beyond this basic view. For example cascaded servers can scale to a much larger meeting or live streaming, especially when participants are geographically distributed and clustered. Separate topology for audio vs. video media paths may enable easy integration and interoperation with telephone and VoIP systems.
In this article, I take a deep dive into WebRTC media path topology — understanding the benefits and tradeoffs of various alternatives — including, but also beyond, the simplified view of full mesh, MCU and SFU.