Re: [Starlink] impressed with my starlink today

[Juliusz Chroboczek <jch@irif.fr>]

> If I understand correctly, galene would support p2p media streams?

No, Galene only does client-server media.  Before I wrote Galene,
I experimented with peer-to-peer WebRTC, and it worked beautifully in
small groups, but collapsed somewhere around 4 to 5 participants.

The problem is not the amount of data (Galene uses at most 700kbit per
flow in the default configuration), but the fact that current WebRTC
implementations require you to encode the video separately for each peer.

> It seems to me that if you have multiple outgoing streams, that if there are
> problems with any of them, a sender-driven system allows for better use of
> what is typically a smaller uplink.

In the sender-driven approach, the receiver gives very detailed feedback
to the sender (lost packets, packet arrival timestamps), who runs the
congestion control algorithm.  In the receiver-driven approach, the
receiver runs the congestion control algorithm, and sends a single integer
to the sender, the maximum allowed rate.  There's nothing that prevents
the sender from reducing the rate below what the receiver requested even
in the receiver-driven algorithm.

Does one of the approaches give more flexibility to the sender?  I'm
frankly not convinced, but perhaps I'll change my mind once I've
implemented it.

-- Juliusz