I recently found this on Reddit while looking into why jellyfin is effected so much by latency. I found that this worked and thought I would share it because it is generally applicable, takes five minutes to setup, and helps a lot with bandwidth on higher latency connections. I admit I am not sure of the technical stuff behind this, so if anyone would like to chime in that would be much appreciated.
Are there any downsides to this? Why isn’t it default if it is so drastically better?
https://en.wikipedia.org/wiki/TCP_congestion_control#TCP_BBR
List some issues, but only earlier version, not BBR3
BBR1:
researchers like Geoff Huston and Hock, Bless and Zitterbart found it unfair to other streams and not scalable.
Hock et al. also found “some severe inherent issues such as increased queuing delays, unfairness, and massive packet loss” in the BBR implementation of Linux 4.9.
Soheil Abbasloo et al. (authors of C2TCP) show that BBRv1 doesn’t perform well in dynamic environments such as cellular networks.
Interesting. I’d be interested in hearing other people’s experience with this. Is this BBR stuff enabled by default on any distros?
I don’t know if it is, but it is really as simple as adding to lines to a config file and restarting a service.
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
Ask more if question
If this is black magic, will I be subject to some sort of witch trial in the near future?
For example unraid (does that count as a distro?) has it enabled by default