[Bloat] Updated Bufferbloat Test

Thu Feb 25 05:49:54 EST 2021

Hi Sina,

great work! I took the liberty to advertise this test already for some weeks, because even in its still evolving developing state it was/is already producubg interesting actionable results. Thanks foe fixing the latency numbers for (desktop) Safari. More below.

> On Feb 24, 2021, at 19:22, Sina Khanifar <sina at waveform.com> wrote:
> 
> Hi all,
> 
> A couple of months ago my co-founder Sam posted an early beta of the
> Bufferbloat test that we’ve been working on, and Dave also linked to
> it a couple of weeks ago.
> 
> Thank you all so much for your feedback - we almost entirely
> redesigned the tool and the UI based on the comments we received.
> We’re almost ready to launch the tool officially today at this URL,
> but wanted to show it to the list in case anyone finds any last bugs
> that we might have overlooked:
> 
> https://www.waveform.com/tools/bufferbloat
> 
> If you find a bug, please share the "Share Your Results" link with us
> along with what happened. We capture some debugging information on the
> backend, and having a share link allows us to diagnose any issues.

	[SM] not a bug, more of a feature request, could you add information on whether the test ran over IPv6 or IPv4, and which browser/user agent was involved (nothing too deep, just desktop/mobile and firefox/chrome/safari/brave/...) as well as the date and time of the test? All of these can help to interpret the test results.

> 
> This is really more of a passion project than anything else for us –
> we don’t anticipate we’ll try to commercialize it or anything like
> that. We're very thankful for all the work the folks on this list have
> done to identify and fix bufferbloat, and hope this is a useful
> contribution. I’ve personally been very frustrated by bufferbloat on a
> range of devices, and decided it might be helpful to build another
> bufferbloat test when the DSLReports test was down at some point last
> year.
> 
> Our goals with this project were:
>  * To build a second solid bufferbloat test in case DSLReports goes down again.
>  * Build a test where bufferbloat is front and center as the primary
> purpose of the test, rather than just a feature.
>  * Try to explain bufferbloat and its effect on a user's connection
> as clearly as possible for a lay audience.
> 
> A few notes:
>  * On the backend, we’re using Cloudflare’s CDN to perform the actual
> download and upload speed test. I know John Graham-Cunning has posted
> to this list in the past; if he or anyone from Cloudflare sees this,
> we’d love some help. Our Cloudflare Workers are being
> bandwidth-throttled due to having a non-enterprise grade account.
> We’ve worked around this in a kludgy way, but we’d love to get it
> resolved.

	[SM] I think this was a decent decision, as it seems your tests has less issues even filling 1Gbps links than most others.

>  * We have lots of ideas for improvements, e.g. simultaneous
> upload/downloads, trying different file size chunks, time-series
> latency graphs, using WebRTC to test UDP traffic etc, but in the
> interest of getting things launched we're sticking with the current
> featureset.

	[SM] Reasonable trade-off, and hopefully potential for pleasant surprises in the future ;)

>  * There are a lot of browser-specific workarounds that we had to
> implement, and latency itself is measured in different ways on
> Safari/Webkit vs Chromium/Firefox due to limitations of the
> PerformanceTiming APIs. You may notice that latency is different on
> different browsers, however the actual bufferbloat (relative increase
> in latency) should be pretty consistent.
> 
> In terms of some of the changes we made based on the feedback we
> receive on this list:
> 
> Based on Toke’s feedback:
> https://lists.bufferbloat.net/pipermail/bloat/2020-November/015960.html
> https://lists.bufferbloat.net/pipermail/bloat/2020-November/015976.html
>  * We changed the way the speed tests run to show an instantaneous
> speed as the test is being run.

	[SM] Great, if only so it feels comparable to "other" speedtests.

>  * We moved the bufferbloat grade into the main results box.

	[SM] +1; that helps set the mood ;)

>  * We tried really hard to get as close to saturating gigabit
> connections as possible. We redesigned completely the way we chunk
> files, added a “warming up” period, and spent quite a bit optimizing
> our code to minimize CPU usage, as we found that was often the
> limiting factor to our speed test results.
>  * We changed the shield grades altogether and went through a few
> different iterations of how to show the effect of bufferbloat on
> connectivity, and ended up with a “table view” to try to show the
> effect that bufferbloat specifically is having on the connection
> (compared to when the connection is unloaded).
>  * We now link from the results table view to the FAQ where the
> conditions for each type of connection are explained.
>  * We also changed the way we measure latency and now use the faster
> of either Google’s CDN or Cloudflare at any given location. We’re also
> using the WebTiming APIs to get a more accurate latency number, though
> this does not work on some mobile browsers (e.g. iOS Safari) and as a
> result we show a higher latency on mobile devices. Since our test is
> less a test of absolute latency and more a test of relative latency
> with and without load, we felt this was workable.
>  * Our jitter is now an average (was previously RMS).
>  * The “before you start” text was rewritten and moved above the start button.
>  * We now spell out upload and download instead of having arrows.
>  * We hugely reduced the number of cross-site scripts. I was a bit
> embarrassed by this if I’m honest - I spent a long time building web
> tools for the EFF, where we almost never allowed any cross-site
> scripts. * Our site is hosted on Shopify, and adding any features via
> their app store ends up adding a whole lot of gunk. But we uninstalled
> some apps, rewrote our template, and ended up removing a whole lot of
> the gunk. There’s still plenty of room for improvement, but it should
> be a lot better than before.
> 
> Based on Dave Collier-Brown’s feedback:
> https://lists.bufferbloat.net/pipermail/bloat/2020-November/015966.html
>  * We replaced the “unloaded” and “loaded” language with “unloaded”
> and then “download active”  and “upload active.” In the grade box we
> indicate that, for example, “Your latency increased moderately under
> load.”
>  * We tried to generally make it easier for non-techie folks to
> understand by emphasizing the grade and adding the table showing how
> bufferbloat affects some commonly-used services.
>  * We didn’t really change the candle charts too much - they’re
> mostly just to give a basic visual - we focused more on the actual
> meat of the results above that.
> 
> Based on Sebastian Moeller’s feedback:
> https://lists.bufferbloat.net/pipermail/bloat/2020-November/015963.html
>  * We considered doing a bidirectional saturating load, but decided
> to skip on implementing it for now. * It’s definitely something we’d
> like to experiment with more in the future.
>  * We added a “warming up” period as well as a “draining” period to
> help fill and empty the buffer. We haven’t added the option for an
> extended test, but have this on our list of backlog changes to make in
> the future.
> 
> Based on Y’s feedback (link):
> https://lists.bufferbloat.net/pipermail/bloat/2020-November/015962.html
>  * We actually ended up removing the grades, but we explained our
> criteria for the new table in the FAQ.
> 
> Based on Greg White's feedback (shared privately):
> * We added an FAQ answer explaining jitter and how we measure it.

[SM] "There are a number of different waus of measuring and defining jitter. For the purpose of this test, we calculate jitter by taking the average of the deviations from the mean latency."

Small typo "waus" instead of "ways".

Best Regards
	Sebastian

> 
> We’d love for you all to play with the new version of the tool and
> send over any feedback you might have. We’re going to be in a feature
> freeze before launch but we'd love to get any bugs sorted out. We'll
> likely put this project aside after we iron out a last round of bugs
> and launch, and turn back to working on projects that help us pay the
> bills, but we definitely hope to revisit and improve the tool over
> time.
> 
> Best,
> 
> Sina, Arshan, and Sam.
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