Re: [Bloat] extremely good dslreports result for bufferbloat on free.fr

[Sebastian Moeller <moeller0@gmx.de>]

Hi Jb,

I wonder the ping RTT plot, does it show all individual RTT-probes, or is it showing an aggregate measure per bar? If aggregate which measure (hopefully the maximum or something close like a high percentile)?


Best Regards
	Sebastian

On May 1, 2015, at 08:31 , jb <justin@dslr.net> wrote:

> >This got an A+ rating, which I would not have given it, given the
> enormous load spike.
> 
> I think there will always be the occasional incorrectly graded test,
> this one is simply because the median of the downstream latency 
> ignores the spike. If I used average(), then it would not ignore
> the spike, however one very high outlier could also ruin a good result.
> After all, pinging anything on the internet can always get the odd
> bad response now and again.
> 
> If neither average nor median is any good, then there needs to be 
> a filter function. But what filter? ignoring spikes that are hugely higher
> than neighbouring ones? that would fail if there was a spike every 3rd
> sample. Open to ideas..
> 
> Here is a result from the australian telco free public hotspot:
>     http://www.dslreports.com/speedtest/399962
> 
> On the side of the hotspot it says 'send us your thoughts about this
> free service'. Well my thought is that if one person posted a picture
> to Instagram, the whole hotspot would be unusable for as long as it
> took to upload. 6 seconds of buffer in there somewhere.
> 
> cheers,
> 
> On Fri, May 1, 2015 at 4:05 PM, Dave Taht <dave.taht@gmail.com> wrote:
> This got an A+ rating, which I would not have given it, given the
> enormous load spike.
> 
> http://www.dslreports.com/speedtest/400387
> 
> Imagine if your steering wheel behaved like this.
> 
> On Thu, Apr 30, 2015 at 8:10 PM, jb <justin@dslr.net> wrote:
> > Already users are like "how can i fix this!".
> 
> The FAQ can be improved.
> 
> > I've just replied to one who has lower speeds on the surfboard SB6141 which
> > is a modem designed for crazy cable speeds. He has an "F" and his downstream
> > bloat is terrible, and upstream not much better.
> >
> > I imagine a LOT of people on slower plans have a "recommended" modem like
> > this one.
> 
> I have not found a cable modem with less than 250ms bloat at 50mbit/5.
> The docsis 3 ones
> are often in the 800 ms range.
> 
> >
> > However most of them will hear that the problems from bloat only happen when
> > you reach maximum upload or download speed and will think, well, I can live
> > with that, I never run my connection to capacity and I don't upload to
> > offsite backups..
> 
> Latency spikes are annoying no matter how they are inflicted, and happen
> all the time on nearly any workload. Your test is testing tcp in steady state,
> most web transactions are bursts of dozens to a hundred flows in slow
> start.
> 
> It is the business class customers that feel it most often. I have never
> visited a business class cable customer that had reasonable amounts of delay
> and jitter during business hours.
> 
> After living in  bloat-free universe for quite some time now, annoying
> issues with things like netflix are decreased, voip and videoconferencing
> work all the time, same for games...
> 
> it would be hard to create a metric
> for user satisfaction, but every before/after comparison someone
> implementing a solution is quite overjoyed.
> 
> https://twitter.com/mnot/status/575581792650018816
> 
> >
> > On Fri, May 1, 2015 at 10:48 AM, Rich Brown <richb.hanover@gmail.com> wrote:
> >>
> >>
> >> > On Wed, Apr 29, 2015 at 9:33 PM, jb <justin@dslr.net> wrote:
> >> > ...
> >> >> if it did get a rating it would be an "D" or "F"..
> >> >
> >> > How about "E" for error? That can be further explained in the text
> >> > "Sometimes the bloat is so bad that we cannot adaquately test for it -
> >> > and other times there is something else badly wrong with the link that
> >> > we cannot identify."
> >>
> >> I would stay away from a letter grade for that state, since it could
> >> appear to be on the continuum of A+, A, B, C, D, E (?) F...
> >>
> >> Better to give it a "-" or "?" mark. And if they hover over the "?", let
> >> the text show: "Sometimes the bloat is so bad that we cannot adaquately test
> >> for it - and other times there is something else badly wrong with the link
> >> that we cannot identify."
> >>
> >> Rich
> >
> >
> 
> 
> 
> --
> Dave Täht
> Open Networking needs **Open Source Hardware**
> 
> https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67
> 
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