Hi,

> Le 21 avr. 2020 à 20:44, Dave Taht <[email protected]> a écrit :
> 
> It has always been my dream, that at least for outbound, there would
> be sufficient backpressure from the driver
> to not have to shape at all, or monitor the link. We have that now in
> BQL and AQL. free.fr's dsl driver "does the right thing" - no other
> dsl driver does.

My curiosity is piqued. Can you elaborate on this? What does free.fr 
<http://free.fr/> do?

Thanks,
Thibaut

> Nor usb network devices. I hope more folk roll up
> their sleeves and test the ath10k some, it's looking lovely from here.
> 
> https://forum.openwrt.org/t/aql-and-the-ath10k-is-lovely/
> 
> next up either the new mediatek chip or intel..
> 
> On Tue, Apr 21, 2020 at 11:40 AM Jonathan Morton <[email protected]> 
> wrote:
>> 
>>> On 21 Apr, 2020, at 9:22 pm, Justin Kilpatrick <[email protected]> wrote:
>>> 
>>> I have a frequently changing link I'm using automated tools to monitor and 
>>> tune using Cake. Currently I'm only tuning bandwidth parameter using 
>>> latency and packet loss data.
>>> 
>>> My reading of the codel RFC seems to say that trying to tune the 'interval' 
>>> value using known path and link latency won't provide any advantages over 
>>> just tuning the bandwidth parameter.
>>> 
>>> Obviously codel is just one part of the Cake setup and I'm wondering if 
>>> there are any advantages I'm missing by not providing this extra input 
>>> using data I already gather.
>> 
>> The default latency parameters are tuned well for general Internet paths.  
>> The median path length on the public Internet is about 80ms, for which the 
>> default interval of 100ms and target of 5ms works well.  Codel is also 
>> designed to accommodate a significant deviation from the expected path 
>> length without too much difficulty.
>> 
>> I think it's only worth trying to adjust this if your typical path is 
>> substantially different from that norm.  If all your traffic goes over a 
>> satellite link, for example, the default parameters might be too tight.  If 
>> the vast majority of it goes to a local CDN, you could try the "metro" 
>> keyword to tighten things up a bit.  Otherwise, you'll be fine.
>> 
>> Also, most protocols are actually not very sensitive to how tight the AQM is 
>> set in the first place.  Either they don't really care about latency at all 
>> (eg. bulk downloads) or they are latency-sensitive but also sparse (eg. DNS, 
>> NTP, VoIP).  So they are more interested in being isolated from the 
>> influence of other flows, which Cake does pretty well regardless of the AQM 
>> settings.
>> 
>> It's *considerably* more important to ensure that your shaper is configured 
>> correctly.  That means setting not only the bandwidth parameter, but the 
>> overhead parameters as well.  A bad shaper setting could result in some or 
>> all of your traffic not seeing Cake as the effective bottleneck, and thus 
>> not receiving its care.  This can be an orders-of-magnitude effect, 
>> depending on just how bloated the underlying hardware is.
>> 
>> - Jonathan Morton
>> _______________________________________________
>> Cake mailing list
>> [email protected]
>> https://lists.bufferbloat.net/listinfo/cake
> 
> 
> 
> -- 
> Make Music, Not War
> 
> Dave Täht
> CTO, TekLibre, LLC
> http://www.teklibre.com
> Tel: 1-831-435-0729
> _______________________________________________
> Cake mailing list
> [email protected]
> https://lists.bufferbloat.net/listinfo/cake

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