Does WebRTC allow one-to-many (multicast) connections?

Question

I've read a lot about WebRTC, but there's one question that still remains. I hope you can help me with that:

Does WebRTC allow me to create a one-to-many connection? I don't mean "being able to have multiple connections to different computers", I really talk about having one connection that multicasts its data to multiple endpoints without the need to "upload" the data once for each endpoint. Will it be possible to send one single package to the web, that, when it reaches the web, magically splits itself into multiple packages with different targets?

I hope you get what I'm looking for :)

Until now, I've only seen one-to-one connections, or solutions that have one connection to a central server that does the multicast for them (which usually results in twice the ping).

But to me, one-to-one connections don't seem to be really useful (due to low upload-bandwith of clients), and solutions with a central server are also possible without WebRTC (using WebSockets), so the only real use case for WebRTC would be one-to-many connections.

So.. is this something that will be possible in the future? Or is it already possible today?

Answer 1

Three things:

1. IP multicast in the Internet is not possible at the moment (multicast addresses are not routed by ISPs)
2. WebRTC fits many use cases beyond one-to-many communication, just have a look at this document: https://datatracker.ietf.org/doc/html/draft-ietf-rtcweb-use-cases-and-requirements-06
3. WebRTC connections between browsers are always encrypted (using SRTP for A/V data and DTLS for generic data) and the encryption parameters (session keys etc.) are negotiated for every connection separately. How would you do that in a multicast environment (think of it as a distribution tree)?

So no, WebRTC cannot be used with IP multicast.