From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x22e.google.com (mail-ob0-x22e.google.com [IPv6:2607:f8b0:4003:c01::22e]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 1F73921F2D5 for ; Fri, 1 May 2015 01:10:58 -0700 (PDT) Received: by obcux3 with SMTP id ux3so61485222obc.2 for ; Fri, 01 May 2015 01:10:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=qI6WnWfSx/8B7puoDDiRd40jo8O+X4RjPhrnYZC4vXo=; b=XJR5nW0VHQdYFb0MpJyltsqYVp0XgG8vhmAcH5/zFY1DzUiwjK67TouUpnE1apW576 AMqVz9GLVLFEv+J47hMH648ZeTbV6aGB33FK0yuHAYCyJqMZkFgwAzdRuqPpAlhDKdj0 oiWZx7P7YiJnqXqEfJaldkOZ/rnuPmRQKU+moWRb5uoH4416smq8PJBqDhJQ/sC26NOG XzwNzvh0jTOgsF6u3PIDmLdNGwW69cLSAJ39mUp6lHSWyl69ITs/Zo+Qdc6ZxOklyPI8 7A9FepUHt3SCfCQB2qfxGINq8EKySKn8xWKr+nG1n6rRKmA52+vG4EXAR8lhaWny/ZP/ i8PQ== MIME-Version: 1.0 X-Received: by 10.60.103.36 with SMTP id ft4mr6779672oeb.39.1430467857798; Fri, 01 May 2015 01:10:57 -0700 (PDT) Received: by 10.202.71.139 with HTTP; Fri, 1 May 2015 01:10:57 -0700 (PDT) In-Reply-To: References: <87618e6gkm.wl-jch@pps.univ-paris-diderot.fr> <58258E43-953F-4A3B-ABC0-EA4193CC67C1@gmail.com> Date: Fri, 1 May 2015 01:10:57 -0700 Message-ID: From: Dave Taht To: jb Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: bloat Subject: Re: [Bloat] extremely good dslreports result for bufferbloat on free.fr X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 May 2015 08:11:27 -0000 On Thu, Apr 30, 2015 at 11:31 PM, jb 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 highe= r > than neighbouring ones? that would fail if there was a spike every 3rd > sample. Open to ideas.. 98th percentile across the cdf? (It would be interesting to calculate this across your data set thus far, regardless) Use two measurements - one of jitter one of median latency increase? > 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. Gotta start somewhere.... > > cheers, > > On Fri, May 1, 2015 at 4:05 PM, Dave Taht 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 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 happe= n >> > 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 videoconferencin= g >> 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 >> > wrote: >> >> >> >> >> >> > On Wed, Apr 29, 2015 at 9:33 PM, jb 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 i= t >> >> > - >> >> > 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 adaquate= ly >> >> test >> >> for it - and other times there is something else badly wrong with the >> >> link >> >> that we cannot identify." >> >> >> >> Rich >> > >> > >> >> >> >> -- >> Dave T=C3=A4ht >> Open Networking needs **Open Source Hardware** >> >> https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67 > > --=20 Dave T=C3=A4ht Open Networking needs **Open Source Hardware** https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67