According to multiple debian based and ubuntu based and Arch I use. No. Not default. Cubic still is.

My experience was that some days ago I was trying to make my UDP faster, but turned out found out about BBR - for TCP. Well, lucky me - currently some country away from home for family reason. Plex generally takes 40-80s to start a movie/episode for me. And measly about 10s max buffer available - and this is on a 3-5Mbps show.

After BBR (note I have to apply on Proxmox host, my container are unprivileged and can’t set this themselves), I got 8-30s max to start a show/movie. And now comfortably sit between some good minutes on buffer. 15-20Mbps quality now playable.

To me personally it was black magic, and I was tossing it in just 2 days ago too

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But there is an ubuntu server oddnumber.not-04?