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BBR, the new kid on the TCP block

(blog.apnic.net)
360 points pjf | 1 comments | 09 May 17 08:56 UTC | HN request time: 0.224s | source
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skyde ◴[09 May 17 14:52 UTC] No.14300495[source]▶
How can we use it today! Is it in Linux code already and easy to enable ?
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Scaevolus ◴[09 May 17 16:44 UTC] No.14301568[source]▶
It's available in Ubuntu 17.04. Add these lines to /etc/sysctl.conf:

    net.core.default_qdisc=fq
    net.ipv4.tcp_congestion_control=bbr
I got 400Mbps (on a 1Gbps link) from Seattle to New York with a single TCP-BBR stream, vs ~50Mbps before :-).
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1. otterley ◴[10 May 17 14:25 UTC] No.14308410[source]▶
You could probably saturate that link with a single TCP stream -- even without BBR -- by simply choosing the correct send and receive buffer sizes in your test program. (I assume you're using iperf or a similar program to perform your tests.)

BBR and other congestion-control algorithms come into play when the underlying IP network is congested. To test them, you have to have control of the congestion rate of the underlying circuit, which you might not have if you're testing this on an ordinary public IP network.