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

Dave Taht dave.taht at gmail.com
Sat Jul 21 17:37:29 EDT 2018

or, another way we might look at it is there is very little we can do
as the cmts has to have data in it in order to burst schedule the mac
for the next string of packets, much like how fq_codel for wifi has
"one in the hardware, one ready to go", a cmts has at least one in the
hardware (per channel? a multiple? what?).

or I could be on drugs entirely. And this thread did start with
fast.com misbehaving badly regardless of the shaper in place or not,
which is not what I'm looking at now.  I need to setup a 45ms rtt

anyway, as per your suggestion, the latency gets MUCH better with your
hping3 idea running, which implies that we've  been fooled all along
by the rrul test. On the other hand, I think this will hurt other
cable modems on the same wire. On the gripping hand, I'm happier
knowing that with a busier network, docsis cable, when shaped, gets
better, and that I should junk my existing test cablemodem due to the
persistent spikes I see.

I wonder if it's the sent path or the return path shattering latency
so well? I wonder if hping3 would count against your badwidth cap?

going back to trying to figure out why fast.com is so gnarly
On Sat, Jul 21, 2018 at 2:18 PM Arie <nospam at ariekanarie.nl> wrote:
> I had a similar issue with my previous cable modem, whatever I shaped to didn't matter, I still had long delays. I "fixed" it by continuously sending a stream of empty UDP packets upstream:
> hping3 -2 -d 0 -s 10080 -k -p 80 -i u150 IP-OF-FIRST-OUTSIDE-CABLE-HOP-HERE
> On 21 July 2018 at 22:36, Dave Taht <dave.taht at gmail.com> wrote:
>> This is my "inbound trying to shape a cable connection" smoking gun.
>> The delay curve is the same
>> shaping the 110mbit cmts down to 85mbit OR 55mbit.
>> _______________________________________________
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>> Cake at lists.bufferbloat.net
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Dave Täht
CEO, TekLibre, LLC
Tel: 1-669-226-2619
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