From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (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 BB0F63B29D for ; Mon, 17 May 2021 01:18:58 -0400 (EDT) Received: by mail-pl1-f182.google.com with SMTP id 69so2472918plc.5 for ; Sun, 16 May 2021 22:18:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=oYPPy4BUIrUECZzEqw1QiSfhKnw0VzMRuB84Ze1YqVM=; b=rdCbHwI4q3jh4LGa755wHXFgSFkQ6bv1XnoePX7gua32w60+3sCCuh4MuiUBECf3uz KetxTBv6u2iSZdc1PUH9AEydDTfST2NvZ8WTvisoLIYwrXWUfesEKJnwcld6XnNf/9UL 7mrE4m35q/tPev+rmoY0JJ1SSqav5M6v0JNmnLnQQ09yYpmJplnKrcu2twjRr1plHYRf tISDLST7C9H1QHWw57DFK7rckPLNxEIdVc/qAKK0nlUxyEPrWibx0/y8nBppY6bGGJ3i oZ5FieIETafbgSzkfVQ8GXzfRDDxT4zfCn9Dtv49+CCIQHD8HnR7FkHbVS4JyIM/IidU ydnA== X-Gm-Message-State: AOAM532z2Kx5JTzM7EQ5FAWI1wuS9nGHqQnoFu1UDienaMbQbHz7AjkA 3ZHBD932HfRX835ogWmbwR8ewmHM67w= X-Google-Smtp-Source: ABdhPJye98IA7fJxnLNQACctkFTTCMgBh7tgBmw1d2vOsHVz0hjBgJO9rZdzWPk6LrqeVHgaoY1qYg== X-Received: by 2002:a17:90a:c284:: with SMTP id f4mr7494953pjt.83.1621228737645; Sun, 16 May 2021 22:18:57 -0700 (PDT) Received: from [192.168.130.24] (52-119-118-239.PUBLIC.monkeybrains.net. [52.119.118.239]) by smtp.gmail.com with ESMTPSA id g89sm11398068pjg.30.2021.05.16.22.18.56 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 16 May 2021 22:18:57 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) From: Simon Barber In-Reply-To: Date: Sun, 16 May 2021 22:18:55 -0700 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <97191DFF-F492-4441-B9E6-F34DF37E9307@superduper.net> References: <6d93a3cf-7907-c50b-7903-79bd638b5766@indexexchange.com> To: john X-Mailer: Apple Mail (2.3608.120.23.2.4) Subject: Re: [Bloat] Terminology for Laypeople 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: Mon, 17 May 2021 05:18:58 -0000 Bufferbloat - At every router there are buffers that hold packets about to go out on a = link, incase the packets coming into the router arrive faster than they = can go out. If the packets keep arriving too fast the buffers fill up = and eventually arriving packets have nowhere to go and are dropped. TCP = is a protocol that underlies most data transferred on the internet - = every time you load a webpage for example, you are using TCP. The way = TCP works is by gradually sending data faster and faster until a packet = is dropped, then slowing down a bit before trying to ramp speed up = again, and again, and again for ever. This means that TCP is trying to = keep the buffers in the router that feeds the slowest link in your = connection full (Ramping up it=E2=80=99s speed until a packet is dropped = - i.e. the buffers are full). Unfortunately these days routers have way = more buffers than necessary and every data packets that goes into a = buffer must wait for all the other packets ahead of it in the buffer to = be sent first. This can add seconds of delay to your connection in some = cases. How=E2=80=99s that? Simon > On May 16, 2021, at 11:48 AM, john wrote: >=20 > Hello, > I have been on this mailing list since March this year. I am one of = the=20 > laypeople who is very interested in bufferbloat and have been trying = to=20 > understand what the bufferbloat actually is by reading your email=20 > exchanges. >=20 > I was very happy when the subject: [Bloat] Questions for Bufferbloat=20= > Wikipedia article, came up. I thought someone could finally explain it=20= > with very easy word which I could understand. But the more discussion=20= > goes on the more I got confused and I thought this mailing list is for=20= > aliens exchanging idea not for me human. > :-) >=20 > I also watched Dave's > Making Wifi Fast + Slides - BattleMeshV8 - YouTube > https://www.youtube.com/watch?v=3DRb-UnHDw02o&t=3D1657s > But I still could not really understand exactly what Dave was trying = to=20 > explain in it. >=20 > Then, another subject: [Bloat] Terminology for Laypeople, came up. I=20= > thought I could finally understand what the bufferbloat is. But so far = I=20 > am not even close to the understanding. Now it seems to me that this=20= > mailing list is only for Albert Einstein class scientists to discuss=20= > something super difficult to understand. This is because no one seems = to=20 > be able to explain in a manner laypeople can understand. Or probably = my=20 > effort to understand it is not really enough yet. But I think I have=20= > been really doing my best trying to understand what all of you are=20 > trying to explain about. >=20 > I thought I could not be qualified to even drop a line to this mailing=20= > list because I can not write nor explain in the manner others on this=20= > mailinglist do. I have been hesitating to ask a question. But please=20= > allow me to share with you what image came up in my mind after reading=20= > all the Emails exchanged here since March. >=20 > As of now, I am wondering if the bufferbloat could be explained with=20= > something like a sushi belt-conveyor, the one you may find at the = sushi=20 > restaurant equipped with automated belt-conveyor to bring plates with=20= > sushi to customer's seat. >=20 > In my mind, I am seeing the plate as a packet and the conveyor as=20 > network. For Europeans and Americans, it may be easier to picture the=20= > KrispyKreme's donuts belt conveyor in mind instead of sushi one. = Donuts=20 > are the packets and they go around the network on conveyor in my mind. >=20 > After watching Dave's YouTube video, it seems to me, the congestion of=20= > the packets which Dave was explaining is equivalent to sushi plats on=20= > conveyor stuck on the route and colliding each other on the conveyor=20= > since the conveyor keeps bringing more packets one after another to = the=20 > collision point, then plats overflow from the conveyor and dropped on=20= > the floor. >=20 > So now, my question is the picture I described above is close to what=20= > bufferbloat is? Or I am still very far from understanding? If I am = still=20 > far from understanding, will you be able to explain it to me, the=20 > laypeople, using the sushi or donuts conveyor? Is the problem the = speed=20 > adjustment of the conveyor? Or too many plates or donuts are placed on=20= > the conveyor? If so, why the rate or speed of each factors can not be=20= > adjusted? I even wonder if you could explain it using the door to door=20= > package delivery service since you are talking about delivering = packets. >=20 > By the way, thank you very much for your effort to make the = explanation=20 > of bufferbloat to laypeople! >=20 > john >=20 >=20 >=20 >=20 > --------- Original Message ---------- > Subject: Re: [Bloat] Terminology for Laypeople > From: Dave Collier-Brown > To: bloat@lists.bufferbloat.net > Cc: =20 > Date: Wed, 12 May 2021 17:51:16 -0400 >=20 > "lag" is often understood by non-technical folks, as in "the lag = between=20 > the time you step on the gas and the time the car actually speeds up". > Some folks who've been exposed to video enough will know about "lag = and=20 > jitter" (;-)) >=20 > --dave=20 > On 2021-05-12 11:50 a.m., Ingemar Johansson S via Bloat wrote: >> Hi >=20 > Yes. "Idle latency" and "Working latency" make sense. >=20 > Note however that if you think of idle latency as sparse ping, then=20 > these sparse ping can give unreasonably high values over cellular = access=20 > (4G/5G). The reason is here mainly DRX which is a battery saving=20 > function in mobile devices. More frequent pings like every 20ms over = the=20 > course of 100ms or so can give more correct values. >=20 > /Ingemar >=20 >=20 > Message: 1 > Date: Tue, 11 May 2021 21:26:21 +0000 > From: Greg White > To: Jonathan Foulkes , "Livingood, Jason" > > Cc: bloat > Subject: Re: [Bloat] Terminology for Laypeople > Message-ID: <0A5DF790-7A71-4B84-A20B-559A5E0CE65F@cablelabs.com> > Content-Type: text/plain; charset=3D"utf-8" >=20 > I recently heard Stuart Cheshire (sort of tongue-in-cheek) refer to " > idle > latency" as "the latency that users experience when they are not using=20= > their > internet connection" (or something along those lines). >=20 > I think terminology that reinforces that the baseline (unloaded) = latency=20 > is not > always what users experience, and that latency under load is not=20 > referring to > some unusual corner-case situation, is good. So, I like "idle = latency"=20 > and > "working latency". >=20 > -Greg >=20 >=20 >=20 >=20 >> _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --=20 > David Collier-Brown, | Always do right. This will gratify > System Programmer and Author | some people and astonish the rest > dave.collier-brown@indexexchange.com | -- Mark Twain=20 > = -------------------------------text/plain------------------------------- >=20 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat >=20 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat