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.

  • catch22@startrek.website
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    3 months ago

    Cool! This seems like an good write up on it

    https://atoonk.medium.com/tcp-bbr-exploring-tcp-congestion-control-84c9c11dc3a9

    Bottleneck Bandwidth and Round-trip propagation time (BBR) is a TCP congestion control algorithm developed at Google in 2016. Up until recently, the Internet has primarily used loss-based congestion control, relying only on indications of lost packets as the signal to slow down the sending rate. This worked decently well, but the networks have changed. We have much more bandwidth than ever before; The Internet is generally more reliable now, and we see new things such as bufferbloat that impact latency. BBR tackles this with a ground-up rewrite of congestion control, and it uses latency, instead of lost packets as a primary factor to determine the sending rate.

  • walden@sub.wetshaving.social
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    3 months ago

    Interesting. I’d be interested in hearing other people’s experience with this. Is this BBR stuff enabled by default on any distros?

    • Nanabaz2@lemmy.world
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      3 months ago

      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

    • HumanPerson@sh.itjust.worksOP
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      3 months ago

      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.

    • B0rax@feddit.de
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      3 months ago

      For example unraid (does that count as a distro?) has it enabled by default

    • far_university1990@feddit.de
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      3 months ago

      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.

    • HumanPerson@sh.itjust.worksOP
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      3 months ago

      I believe it will result in like 10% additional overhead, which may be bad on metered connections, but I am not aware of any situation that results in decreased performance. I don’t really know much about this so if anyone would like to correct me, please do.

  • Pixel
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    3 months ago

    Cool writeup. I remember implementing BBR many years ago when I was trying to bypass the Great Firewall for an extended stay. Helped deal greatly with the huge congestion on Chinanet backbone at the time, but it’s less of an issue these days now that foreigners can use CN2.

    • Gooey0210@sh.itjust.works
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      3 months ago

      Sorry, what is CN2?

      If it’s any solution CCP provides, I wouldn’t trust it anyway

      The great firewall situation was always interesting, because if you would use a roaming Sim, then you will be able to access anything

      • Pixel
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        3 months ago

        The great firewall situation was always interesting, because if you would use a roaming Sim, then you will be able to access anything

        Roaming SIMs work because the APN sets a network routing path outside of China.

  • Decronym@lemmy.decronym.xyzB
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    3 months ago

    Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:

    Fewer Letters More Letters
    IP Internet Protocol
    Plex Brand of media server package
    TCP Transmission Control Protocol, most often over IP
    UDP User Datagram Protocol, for real-time communications

    [Thread #681 for this sub, first seen 15th Apr 2024, 22:15] [FAQ] [Full list] [Contact] [Source code]