[kixelated]

SCTP and by extension, WebRTC data channels, are supposed to use the same congestion control algorithms as TCP/QUIC. But I don't know which CC libsctp does these days.

WebTransport in Chrome currently uses CUBIC but the Google folks want to turn on BBR everywhere. It uses the same QUIC implementation as HTTP/3 so it's going to be more battle hardened.

[greenavocado]

SCTP: The FORWARD-TSN chunk was introduced to support selective unreliability: it allows the sender to tell the receiver that it will not retransmit some number of chunks, and requests that the receiver consider all these chunks as received.

[kixelated]

QUIC has a much better alternative to FORWARD-TSN, either via RESET_STREAM or QUIC datagrams.

I've implemented SCTP before to hack in "datagram" support by spamming FORWARD-TSN. Fun fact: you can't use FORWARD-TSN if there's still reliable data outstanding. TSN is sequential after all, you have to drop all or nothing.

QUIC as a protocol is significantly better than SCTP. I really recommend the RFC