ECN is a far more efficient TCP congestion control mechanism that was incorporated in to the TCP standards in 2001 and it was meant to replace Jacobson's AIMD method.

[Navek]’s recent video goes over TCP congestion control, the solution to this problem which allows our much larger modern internet to work. In a 1987 paper, ...

Now when you check which congestion control algorithm is in use (with the command sysctl net.ipv4.tcp_congestion_control), you will see output containing bbr (Figure A). Figure A.

A top-down exploration of networking using the 5-layer model and the TCP/IP stack. HTTP, FTP, DNS, BSD Sockets, concurrent servers, checksums, reliable transport with stop-and-wait, go-back-n, ...