[Cerowrt-devel] [Bloat] android, sqm-autorate and lte and videoconferencing

Wed Apr 20 06:29:06 EDT 2022

Dear Joel, Luis,

Yes exactly; the bash CAKE-autorate implementation seeks to increase
bandwidth on load subject to the RTT not spiking.

I think of it a little like a 'turbo' function on a CPU. It allows
supervised excursions beyond the base bandwidth (safe harbour) for periods
of heavy use, and otherwise returns to the safe harbour. Such supervised
excursions are helpful to allow downloads to finish quicker and without
hurting videoconferencing, and the safe harbour is helpful for general use
when higher CAKE bandwidth is not needed anyway. If even the safe harbour
causes trouble (e.g. a tsunami), it will keep dialing down to the set
minimum bandwidth as required. This is the thinking behind having the set
minimum, base and maximum for both download an dupload.

Whilst the approach seems to be working pretty well on LTE and Starlink
variable connections (I mean for sure it beats just using CAKE with a fixed
bandwidth on my LTE, and there are a few pretty positive reports from
others users), I imagine that it will not help with CPU saturation.

I read a lot of reports about CAKE eating up too many cycles (e.g. on the
RT3200 CAKE tops out at 500Mbit/s), so it seems there is a lot of appetite
for making CAKE more efficient. But this is not my area of expertise.

Kind regards,

Andrew

On Sun, 17 Apr 2022 at 06:28, Luis A. Cornejo <luis.a.cornejo at gmail.com>
wrote:

> It still is Cake underneath doing the work, autorate is just adjusting
> available bandwidth to get the best latency at the best possible bandwidth.
> I would think it's the same limitation. I believe Dave Taht mentioned
> possibly making cake take advantage of multiple cores in the next
> version/rewrite of Cake.
>
> On Fri, Apr 15, 2022 at 4:41 PM Joel Wirāmu Pauling <joel at aenertia.net>
> wrote:
>
>> Whilst I understand it's not designed for High Bandwidth uplinks - how
>> does it scale to 1 to 10Gbit symmetrical (or near symmetrical) uplinks ?
>>
>> One of the problems i've had with Cake is that it becomes CPU bound
>> beyond around 3 or 4 gigabit.
>>
>> On Sat, 16 Apr 2022 at 07:41, Andrew Somerville <aesomerville at gmail.com>
>> wrote:
>>
>>> Dear all,
>>>
>>> Thank you very much for the introduction Sebastian.
>>>
>>> To give some context, my wife and I relocated to the Scottish Highlands
>>> and now rely upon a 4G LTE connection for work and personal use through
>>> Vodafone UK. I have spent quite a lot of time working on this autorate
>>> problem and have tried to leverage Sebastian's expertise in this field as
>>> much as possible. I have tried to keep it as simple as possible with some
>>> rationale and objective criticism behind the major logic. I value feedback
>>> and criticism.
>>>
>>> I now use the bash implementation in my main branch on my RT3200 router
>>> as a service 24/7. I have rewritten it a few times and will do so again, or
>>> switch to another better approach if available. There have been a few ports
>>> of some of the earlier versions like this Golang version (
>>> https://github.com/notsure2/cake-autorate).
>>>
>>> Kind regards,
>>>
>>> Andrew
>>>
>>>
>>> On Wed, 6 Apr 2022 at 22:42, Dave Taht <dave.taht at gmail.com> wrote:
>>>
>>>> it's looking promising.
>>>>
>>>> in trying to get an android to do better this recent ML paper crossed
>>>> my desk:
>>>>
>>>> https://arxiv.org/pdf/2007.02735.pdf
>>>>
>>>> On Wed, Apr 6, 2022 at 1:38 PM Sebastian Moeller <moeller0 at gmx.de>
>>>> wrote:
>>>> >
>>>> > Dear Dave, dear all
>>>> >
>>>> > please, let me introduce Andrew to this list, who is the driving
>>>> force behind CAKE-autorate's design and implementation (which started from
>>>> a more theoretical discussion in the OpenWrt forum before turning into
>>>> something tangible). There are other alternative approaches for the
>>>> rate-tracking problem many discussed in this longish forum thread:
>>>> https://forum.openwrt.org/t/cake-w-adaptive-bandwidth/108848 (which is
>>>> great as this occasionally leads to quite interesting discussion about how
>>>> the different teams tackle common issues) but Andrew's autorate appears to
>>>> the fastest moving with low software requirements (every router should run
>>>> bash anyway ;) ).
>>>> >
>>>> > Kind Regards
>>>> >         Sebastian
>>>> >
>>>> >
>>>> > > On Apr 6, 2022, at 17:43, Dave Taht <dave.taht at gmail.com> wrote:
>>>> > >
>>>> > > For the past several days,  I have been very successfully using
>>>> > > variants of the cake-autorate code to manage my connections on the
>>>> > > boat, for which I use a tether to my laptop.
>>>> > >
>>>> > > https://github.com/lynxthecat/CAKE-autorate
>>>> > >
>>>> > > Although this test claims my link was inadequate for a good
>>>> videoconference
>>>> > >
>>>> > >
>>>> https://www.waveform.com/tools/bufferbloat?test-id=964831e5-30f9-4695-bfbd-b58da0a759f3
>>>> > >
>>>> > > they have all been perfect (and that test was conducted during an
>>>> > > actual zoom conference). The code does not grab as much bandwidth as
>>>> > > it could, when available, but I'll settle for perfect
>>>> > > videoconferencing.
>>>> > >
>>>> > > Anyway... what I used to do was attach the phone to a router shared
>>>> > > boat-wide that did this stuff, but it would be nice to move the
>>>> > > algorithm directly into an android. My hope is that more modern
>>>> > > androids are running a recent enough kernel(?) to have cake, but
>>>> it's
>>>> > > been a long time since I built anything for android, and am
>>>> wondering
>>>> > > if there is a lte/5g tablet or phone or dedicated lte router "out
>>>> > > there" that can be hacked on?
>>>> > >
>>>> > >
>>>> > >
>>>> > > --
>>>> > > I tried to build a better future, a few times:
>>>> > > https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>>>> > >
>>>> > > Dave Täht CEO, TekLibre, LLC
>>>> > > _______________________________________________
>>>> > > Cerowrt-devel mailing list
>>>> > > Cerowrt-devel at lists.bufferbloat.net
>>>> > > https://lists.bufferbloat.net/listinfo/cerowrt-devel
>>>> >
>>>>
>>>>
>>>> --
>>>> I tried to build a better future, a few times:
>>>> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>>>>
>>>> Dave Täht CEO, TekLibre, LLC
>>>>
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