From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 63F3E3B29D for ; Wed, 24 Feb 2021 17:10:50 -0500 (EST) Received: by mail-il1-x12f.google.com with SMTP id e7so3154895ile.7 for ; Wed, 24 Feb 2021 14:10:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=rbigas9EbDnMzOJflZpI2xEhzmugiY9misf7m1IsX1c=; b=tr0inE8t/BsQhKpgIBywDkbCcCkbXjQEtr7SJMQUqvHSXN9GvZG1xXGec8cwYr5nO6 krr7WOrVnRZaXx8TNEGVR4i1YeRXuSQkciFOU0MGQ8og/hVsAM6AS73kc+SsVAZMcw6m aM6Benb4WAq1RLDIW5joWlYxUY0M0F8+Ferrrb9kFV0eEiAxxXnswHO9dS0J3zbALu+K RUhDOvr9tz7W6J/pfuJBnnM+PkZfOGshDOqMfOUaeO7zzUVg+By9agjhQPgvyk7NA66y DvXk/blAB+4U4jhsL68kqJxtGKuFkf5ckyVAZuwaeQDWjepNidDlP5Jd7GzQert3sSAn V6vg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=rbigas9EbDnMzOJflZpI2xEhzmugiY9misf7m1IsX1c=; b=KIkKZV/97EVpCvbAjVVYjlzG9dEK/JHn9sBbN24L7Pp6Go+SZiwML4MW3xylY8CiB1 3QwvCtThkVwVfCu9iudvu4FM8PJ3gTdmloQg1/0/7ZIG5k8zFWZY5qVDi9hbmc+uaVy7 Po/8Ap6BDwzwJfgGwAHtndvonpgKCxgt2vNC503170gUANNSpRB+xvb4vQFJWc2IZIxc 5HpoMrSXa3phQKYYAytIRMBw4HULpEfLixqMEEdl1+YYJCNezV8rVGGkCta/TrR68YjW /X9Z3xSdZIDMtafSxldNednz5s+CMhYv1Qib0BCSiNy+KyowhiORBc7kT15SzwSvK+wY 187g== X-Gm-Message-State: AOAM530x9MSv+pqgbq5KZOmq3tA8Fc7lrCheCXvXG6uFT7OEVKfWyVP6 oOvQ1B8hsJdVbo+pX0ObHcx4+3nHMcbZlFxeRZE= X-Google-Smtp-Source: ABdhPJysqhEA6qFcPTEjMp6/TCjxAyBJwIDDfypMfOTGdvlPLYtWLX+7+KYNb9FLzOyL+B666N2yksRJG0fDwRBW4bM= X-Received: by 2002:a92:da11:: with SMTP id z17mr6988346ilm.45.1614204649608; Wed, 24 Feb 2021 14:10:49 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Dave Taht Date: Wed, 24 Feb 2021 14:10:38 -0800 Message-ID: To: Sina Khanifar Cc: bloat , sam@waveform.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Bloat] Updated Bufferbloat Test X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Feb 2021 22:10:50 -0000 So I've taken a tiny amount of time to run a few tests. For starters, thank you very much for your dedication and time into creating such a usable website, and faq. I have several issues though I really haven't had time to delve deep into the packet captures. (others, please try taking em, and put them somewhere?) 0) "average" jitter is a meaningless number. In the case of a videoconferencing application, what matters most is max jitter, where the app will choose to ride the top edge of that, rather than follow it. I'd prefer using a 98% number, rather than 75% number, to weight where the typical delay in a videoconfernce might end up. 1) The worst case scenario of bloat affecting a users experience is during a simultaneous up and download, and I'd rather you did that rather than test them separately. Also you get a more realistic figure for the actual achievable bandwidth under contention and can expose problems like strict priority queuing in one direction or another locking out further flows. 2) I get absurdly great results from it with or without sqm on on a reasonably modern cablemodem (buffercontrol and pie and a cmts doing the right things) This points to any of number of problems (features!) It's certainly my hope that all the cdn makers at this point have installed bufferbloat mitigations. Testing a cdn's tcp IS a great idea, but as a bufferbloated test, maybe not so much. The packet capture of the tcp flows DOES show about 60ms jitter... but no loss. Your test shows: https://www.waveform.com/tools/bufferbloat?test-id=3D6fc7dd95-8bfa-4b76-b14= 1-ed423b6580a9 And is very jittery in the beginning of the test on its estimates. I really should be overjoyed at knowing a cdn is doing more of the right things, but in terms of a test... and linux also has got a ton of mitigations on the client side. 3) As a side note, ecn actually is negotiated on the upload, if it's enabled on your system. Are you tracking an ecn statistics at this point (ecnseen)? It is not negotiated on the download (which is fine by me). I regrettable at this precise moment am unable to test a native cablemodem at the same speed as a sqm box, hope to get further on this tomorrow. Again, GREAT work so far, and I do think a test tool for all these cdns - heck, one that tested all of them at the same time, is very, very useful. On Wed, Feb 24, 2021 at 10:22 AM Sina Khanifar wrote: > > Hi all, > > A couple of months ago my co-founder Sam posted an early beta of the > Bufferbloat test that we=E2=80=99ve 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=E2=80=99re almost ready to launch the tool officially today at this UR= L, > 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. > > This is really more of a passion project than anything else for us =E2=80= =93 > we don=E2=80=99t anticipate we=E2=80=99ll try to commercialize it or anyt= hing 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=E2=80=99ve 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=E2=80=99re using Cloudflare=E2=80=99s CDN to perfo= rm 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=E2=80=99d love some help. Our Cloudflare Workers are being > bandwidth-throttled due to having a non-enterprise grade account. > We=E2=80=99ve worked around this in a kludgy way, but we=E2=80=99d love t= o get it > resolved. > * 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. > * 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=E2=80=99s 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. > * We moved the bufferbloat grade into the main results box. > * We tried really hard to get as close to saturating gigabit > connections as possible. We redesigned completely the way we chunk > files, added a =E2=80=9Cwarming up=E2=80=9D 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 =E2=80=9Ctable view=E2=80=9D 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=E2=80=99s CDN or Cloudflare at any given location. We=E2= =80=99re 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 =E2=80=9Cbefore you start=E2=80=9D text was rewritten and moved a= bove 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=E2=80=99m 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=E2=80=99s still plenty of room for improvement, but it sh= ould > be a lot better than before. > > Based on Dave Collier-Brown=E2=80=99s feedback: > https://lists.bufferbloat.net/pipermail/bloat/2020-November/015966.html > * We replaced the =E2=80=9Cunloaded=E2=80=9D and =E2=80=9Cloaded=E2=80= =9D language with =E2=80=9Cunloaded=E2=80=9D > and then =E2=80=9Cdownload active=E2=80=9D and =E2=80=9Cupload active.= =E2=80=9D In the grade box we > indicate that, for example, =E2=80=9CYour latency increased moderately un= der > load.=E2=80=9D > * 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=E2=80=99t really change the candle charts too much - they=E2= =80=99re > mostly just to give a basic visual - we focused more on the actual > meat of the results above that. > > Based on Sebastian Moeller=E2=80=99s 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=E2=80=99s definitely something w= e=E2=80=99d > like to experiment with more in the future. > * We added a =E2=80=9Cwarming up=E2=80=9D period as well as a =E2=80=9C= draining=E2=80=9D period to > help fill and empty the buffer. We haven=E2=80=99t added the option for a= n > extended test, but have this on our list of backlog changes to make in > the future. > > Based on Y=E2=80=99s 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. > > We=E2=80=99d love for you all to play with the new version of the tool an= d > send over any feedback you might have. We=E2=80=99re going to be in a fea= ture > 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. > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat --=20 "For a successful technology, reality must take precedence over public relations, for Mother Nature cannot be fooled" - Richard Feynman dave@taht.net CTO, TekLibre, LLC Tel: 1-831-435-0729