How internet congestion control actually works in the bufferbloat age
Room 7 | Wed 15 Jan | 2:25 p.m.–3:10 p.m.
Presented by
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Dave Taht
@mtaht
https://www.bufferbloat.net
Dave Taht has been involved with Linux since version .99pl15 - first deploying it as part of his ISP in 1994, moving onto being one of the first inventors of the linux based embedded wifi AP in 1998, to helping create the embedded linux market with MontaVista in the early 00's, to working on wireless mesh networks and OLPC.
In his most recent work of the last 8 years, he's tried to tackle some of the biggest problems the Internet has today - Edge computing (especially home routers), IPv6, security, and network latencies (a.k.a "bufferbloat") all through the Linux stack. All stacks, and standards in the IETF (rfc8290), actually.
Dave Taht
@mtaht
https://www.bufferbloat.net
Abstract
You start a big upoad or download, and your ssh connection goes to heck, web pages get delayed, your videoconference glitches, or you start missing your opponents in your game. Bufferbloat is one cause. While the bufferbloat problem is largely fixed in Linux, it's rarely configured properly on the gateways, and thus remains at epidemic proportions across the Internet - and this talk touches upon how to configure that stuff properly - but... why does the network get slow? *How* is the network supposed to deal with overload? This talk is a deep dive into how TCP is supposed to work, and goes into concepts like Slow Start, Congestion Avoidance, windowing, fair queuing and active queue management, the roles of packet drop and ECN, and alternate tcp's and transports such as BBR and QUIC, in the hope that deeper knowledge of how our most basic network transports work will lead to the design and implementation of better systems on top of them.
There will be a couple live demos using humans as packets, and there will be a quiz !
Linux Australia: http://mirror.linux.org.au/pub/linux.conf.au/2020/room_7/Wednesday/How_internet_congestion_control_actually_works_in_the_bufferbloat_age.webm
YouTube: https://www.youtube.com/watch?v=ZeCIbCzGY6k
You start a big upoad or download, and your ssh connection goes to heck, web pages get delayed, your videoconference glitches, or you start missing your opponents in your game. Bufferbloat is one cause. While the bufferbloat problem is largely fixed in Linux, it's rarely configured properly on the gateways, and thus remains at epidemic proportions across the Internet - and this talk touches upon how to configure that stuff properly - but... why does the network get slow? *How* is the network supposed to deal with overload? This talk is a deep dive into how TCP is supposed to work, and goes into concepts like Slow Start, Congestion Avoidance, windowing, fair queuing and active queue management, the roles of packet drop and ECN, and alternate tcp's and transports such as BBR and QUIC, in the hope that deeper knowledge of how our most basic network transports work will lead to the design and implementation of better systems on top of them. There will be a couple live demos using humans as packets, and there will be a quiz ! Linux Australia: http://mirror.linux.org.au/pub/linux.conf.au/2020/room_7/Wednesday/How_internet_congestion_control_actually_works_in_the_bufferbloat_age.webm YouTube: https://www.youtube.com/watch?v=ZeCIbCzGY6k