From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-x230.google.com (mail-pl0-x230.google.com [IPv6:2607:f8b0:400e:c01::230]) (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 E79F73B29E for ; Sat, 25 Nov 2017 15:24:15 -0500 (EST) Received: by mail-pl0-x230.google.com with SMTP id u14so6178662plm.8 for ; Sat, 25 Nov 2017 12:24:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=martingeddes-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to:cc; bh=W9MUQCqdX+wWaUa5BPL2FdPxIKDgiHpNgGQtqkgHoEs=; b=E0LDAZlHj9dl2gpl2Fku+3mTinFfWuDb+FpKhIovvW7b3FQUolEY5xffUMGog99I17 PhdlD7j0EKGWNRvlgzP+Z5o1tm7XhWGu7YDNSUNp9Zwj9dZ2dR9BH6V58zniwADvrh/c h24SUi/7BCdrpXJR42snXYffCB0QqVCsiB3AWklmo4okLjPqvhhQhptxiSJAL8ZC7RjE 1SJQF6g93XrG6MApUxSbAPy94tunCoslcgs8tv7eqCgo91XKTA3bk9nRvqnMD03HBkbN 5qFzxkKHWdrKAmZv03HKrMmyNwC8853d6POVIU/AWDr/I+BenWBT2D4Sg5uH6fN5d/hT ZcRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=W9MUQCqdX+wWaUa5BPL2FdPxIKDgiHpNgGQtqkgHoEs=; b=YRl8dbMJa0ErCqWxbT6K9Z1WE/LxFpVYGxJl2wMKF7q3thWYbIkgqVBFFM5Qa84BO9 r/RJjeoX1QBFwmiZBZqYO0SYmBpUa73kHn/aod3eHY/UJtPnetMhXVDJKiihmh2mEvM7 XFpjj3yeLlfMU0PZRHbLwnfocrc9QudEVTpwwC4ddylH+V5m38sBHZVqt7zXBZxs/CDX XuoANcc+GdgmUn9CyIC5kcGjSW7CBjYeQ3RRbTxRM5DPbuuBoqPr9YCFZQuQF3cCci4q P+re45qA/Aw2HD6Ph/F/K29wO8Bs/pf80vZGOWqygBUllV0+1qepMuSEpBfxMuvihd3Z tkIw== X-Gm-Message-State: AJaThX6/A/sSFquwDH304Y73Liaf2K6lvvEHb9nNM/qd5j6MUEMHuZOu Sh5wVfcmgd82mZ2GtH7woR9kHRe75n9GR3rw2UBuS6kq X-Google-Smtp-Source: AGs4zMaM+CuaSLjyXbaaQJKk+FBE0X0LMsFkN8F50T5bxENXHAz0Aw09+rG8Oh9z1DVNFtdqOZJLuf4lW2h2x0TLsNw= X-Received: by 10.84.239.1 with SMTP id w1mr27879693plk.227.1511641454959; Sat, 25 Nov 2017 12:24:14 -0800 (PST) MIME-Version: 1.0 Received: by 10.100.178.234 with HTTP; Sat, 25 Nov 2017 12:23:54 -0800 (PST) From: Martin Geddes Date: Sat, 25 Nov 2017 20:23:54 +0000 Message-ID: To: Dave Taht Cc: bloat Content-Type: multipart/alternative; boundary="94eb2c1ceaf2f37752055ed473f0" Subject: Re: [Bloat] Bufferbloat in high resolution + non-stationarity 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: Sat, 25 Nov 2017 20:24:16 -0000 --94eb2c1ceaf2f37752055ed473f0 Content-Type: text/plain; charset="UTF-8" Hi Dave, The data was being taken from general network traffic from multiple opcos for a tier 1 global network operator. The task wasn't to fix or improve anything, but to merely establish the baseline quality of the network as-is. What is different about these metrics is the ability to extract the underlying causality, and to be able to (de)compose complete supply chains in a scientific manner (that would stand up in court). If you can capture timing data of the same packet passing multiple probing points, then you can use preexisting measurement capture systems. What matters if getting multi-point distributions, rather than single-point averages. The inherent limitation of AQM is its goal: constructing exemplars of "success modes" for differential flow treatment, without considering what the "failure mode" risks are (which are significant and serious). That said, it prolongs the life of the current infrastructure, buying time to address the underlying science and engineering issues (like work conservation, emergent performance outcomes, and loss/delay trading that conflates degrees of freedom). It doesn't matter what scheduling algorithm you build if it creates arbitrage or denial-of-service attacks that can arm a systemic collapse hazard. The good news is we have a new class of scheduling technology (that works on a different paradigm) that can fully address all of the requirements. We are currently deploying it to enable the world's first commercial quality-assured broadband service. Martin On 16 October 2017 at 21:26, Dave Taht wrote: > > Sorry for the late reply. > > Martin Geddes writes: > > > Folks, > > > > I have uploaded a presentation of high-fidelity network performance > measures > > which includes an example of bufferbloat in high resolution, as possibly > you > > have never seen it before. > > Well, flent can generate a similar level of detail under a generated > load. Some of kathie's work can now do it against tcp on pcaps. > > Was yours against general traffic? > > > > > See slide 18 of this deck: > > https://www.slideshare.net/mgeddes/stationarity-is-the-new-speed. The > classic > > "bloat" is a sudden formation of the queue, and a very slow (and steady) > > draining. Bufferbloat is just one form of statistical variability > > ("non-stationarity") in packet networks. > > Good set of slides. Analysis is picking up... > > Where you and I always tend to fall off a cliff is on your conclusions > as to what to do about it, e.g. slide 19. I'd rather love it if you > repeated your tests and graphs against pie, and fq_codel, and/or cake. > > For that matter BBR might be interesting against your tool. > > And then say what you'd do differently. In some way I can repeat. > > > For a world record winner, see this one where packets take over a minute > (Huawei > > WiFi hotspot roaming in Ireland with UK SIM)! Or for a pretty picture of > buffers > > draining, try this one. > > Well, at the moment gogo-in-flight holds the interplanetary record > (680sec as I recall), but yea, 60+ seconds is up there. Contact > Guinness! > > > > > Happy to answer any questions. > > > > Martin Geddes > > > > > > _______________________________________________ > > Bloat mailing list > > Bloat@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/bloat > --94eb2c1ceaf2f37752055ed473f0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Dave,

The data was being taken from = general network traffic from multiple opcos for a tier 1 global network ope= rator. The task wasn't to fix or improve anything, but to merely establ= ish the baseline quality of the network as-is.

What is d= ifferent about these metrics is the ability to extract the underlying causa= lity, and to be able to (de)compose complete supply chains in a scientific = manner (that would stand up in court). If you can capture timing data of th= e same packet passing multiple probing points, then you can use preexisting= measurement capture systems. What matters if getting multi-point distribut= ions, rather than single-point averages.

The inher= ent limitation of AQM is its goal: constructing exemplars of "success = modes" for differential flow treatment, without considering what the &= quot;failure mode" risks are (which are significant and serious). That= said, it prolongs the life of the current infrastructure, buying time to a= ddress the underlying science and engineering issues (like work conservatio= n, emergent performance outcomes, and loss/delay trading that conflates deg= rees of freedom).

It doesn't matter what sched= uling algorithm you build if it creates arbitrage or denial-of-service atta= cks that can arm a systemic collapse hazard. The good news is we have a new= class of scheduling technology (that works on a different paradigm) that c= an fully address all of the requirements. We are currently deploying it to = enable the world's first commercial quality-assured broadband service.<= /div>

Martin

On 16 October 2017 at 21:26, Dave Taht <dave@taht.net&= gt; wrote:

Sorry for the late reply.

Martin Geddes <mail@martingedde= s.com> writes:

> Folks,
>
> I have uploaded a presentation of high-fidelity network performance me= asures
> which includes an example of bufferbloat in high resolution, as possib= ly you
> have never seen it before.

Well, flent can generate a similar level of detail under a generated=
load. Some of kathie's work can now do it against tcp on pcaps.

Was yours against general traffic?

>
> See slide 18 of this deck:
> https://www.slideshare.net/mgeddes/stationarity-is-the-new-speed. The classic
> "bloat" is a sudden formation of the queue, and a very slow = (and steady)
> draining. Bufferbloat is just one form of statistical variability
> ("non-stationarity") in packet networks.

Good set of slides. Analysis is picking up...

Where you and I always tend to fall off a cliff is on your conclusions
as to what to do about it, e.g. slide 19. I'd rather love it if you
repeated your tests and graphs against pie, and fq_codel, and/or cake.

For that matter BBR might be interesting against your tool.

And then say what you'd do differently. In some way I can repeat.

> For a world record winner, see this one where packets take over a minu= te (Huawei
> WiFi hotspot roaming in Ireland with UK SIM)! Or for a pretty picture = of buffers
> draining, try this one.

Well, at the moment gogo-in-flight holds the interplanetary record (680sec as I recall), but yea, 60+ seconds is up there. Contact
Guinness!

>
> Happy to answer any questions.
>
> Martin Geddes
>
>
> _______________________________________________
> Bloat mailing list
> Bloat@lists.bufferbloat= .net
> https://lists.bufferbloat.net/listinfo/bloat

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