Re: [Cake] inbound cake or fq_codel shaping fails on cable on netflix reno

[Tristan Seligmann <mithrandi@mithrandi.net>]

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Here's my results from South Africa. Ping test while running the fast.com
test, and the tcp_ndown test, running Cake on an EdgeRouter X. I get 140 /
140 Mbps on the fast.com test with 1ms unloaded and 6ms loaded.

Not sure why throughput is so low, but I often see something like this on
artificial bandwidth tests; it peaks close to 200, but then drops back down
toward the end of the test. I'm shaping to 200 / 200 Mbps with cake which
is my sold connection speed; the actual link is 1 Gbps active ethernet over
fibre with the ISP limiting to about 210-220 Mbps.

On Tue, 24 Jul 2018 at 17:19 Dave Taht <dave.taht@gmail.com> wrote:

> cdfs help. I also try to encourage sending the flent.gz files too. :)
>
> Outbound, to 99% or more of the rate, *with perfect framing* looks great
> so far, 'cept on crappy cablemodems.
>
> I am concerned about recommending values as high as 98% for inbound
> shaping. We are engineering to
> the test here (2? 3 flows? on a very short rtt), and need to leave *some*
> headroom for multiple flows to enter in slow start and get kicked out of it.
>
> I'll buy that the old 85% figure made sense in the sub 20Mbit era, and
> that we only need enough headroom to allow X flows to enter based on the
> characteristics of the link and typical traffic - 15 new flows per second
> * per active user/10 ? and cake's response to slow start is more
> agressive...
>
> try a:
>
> flent -H flent-london.bufferbloat.net -s .02 --te=download_streams=32 -t
> '98%' tcp_ndown
>
> with htb+fq_codel and cake to see that spike more clearly.
>
>
> On Tue, Jul 24, 2018 at 7:54 AM Kevin Darbyshire-Bryant <
> kevin@darbyshire-bryant.me.uk> wrote:
>
>>
>>
>> On 24 Jul 2018, at 14:51, Dave Taht <dave.taht@gmail.com> wrote:
>>
>> Now that you can join the party, I note there IS a flent server in
>> england with irtt on it.
>>
>> flent-london.bufferbloat.net
>>
>>
>> Ok, well if you’re desperately interested….. :-)
>>
>> Plot I did running to the london server, one shaped at 99% downstream,
>> the other at 98%…. and I’ve decided to stick at 98% as a result - plot is a
>> little bit hard to distinguish but I’d say there’s around 8ms avg less
>> latency-ish between the two.  And an order of magnitude between using
>> london v fremont :-)
>>
>> The upstream barely registers
>>
>> # tc -s qdisc show dev ifb4eth0
>> qdisc cake 801a: root refcnt 2 bandwidth 78400Kbit diffserv3 dual-dsthost
>> nat ingress split-gso rtt 100.0ms ptm overhead 26
>>
>>
>>
>
> --
>
> Dave Täht
> CEO, TekLibre, LLC
> http://www.teklibre.com
> Tel: 1-669-226-2619
> _______________________________________________
> Cake mailing list
> Cake@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cake
>

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