From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vb0-f43.google.com (mail-vb0-f43.google.com [209.85.212.43]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 792DD200619; Mon, 26 Nov 2012 07:27:46 -0800 (PST) Received: by mail-vb0-f43.google.com with SMTP id fn1so10143649vbb.16 for ; Mon, 26 Nov 2012 07:27:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=XRKA7TJAPl55VNKZTaFN7qkthmylmncB3mQ+pNhDsHg=; b=aOiKzB1KrnhAMRrkgVoVxwyBxIabKsXmIV3s4wSqMcgPfSIrgI3mcGODMbGJrrhAMv Or0LlpFOFtDXmuwW12KCVeem3DZcXLUmKTlVmsTIzztWihuMimd9wT067ywRZGmyoIRQ Zb7rSNpl6xMfvM/3VTdBiZpOS4vhJRmOEO2lnfuuxvjXdojhE0D224dFJ92kUvoHaQKU VeyMYYQq/lVcA89iYWorbT6GAJ0UVoRyaP0rqp3yrVkE/DFkmGKWBJ9nYCILlZm8eSfx 44HlKTjNkEyWln6UzvatG68YvaM8iN0jjyRuYkSt0A6cREWzZWcNWVQJ9p7W5lxPCDve QRcw== MIME-Version: 1.0 Received: by 10.52.180.10 with SMTP id dk10mr17073683vdc.101.1353943664853; Mon, 26 Nov 2012 07:27:44 -0800 (PST) Sender: gettysjim@gmail.com Received: by 10.58.151.202 with HTTP; Mon, 26 Nov 2012 07:27:44 -0800 (PST) In-Reply-To: References: <20121125232034.GF24680@merlins.org> Date: Mon, 26 Nov 2012 10:27:44 -0500 X-Google-Sender-Auth: D_TDq6-3AAxhdFCvG9qiAcIg4m4 Message-ID: From: Jim Gettys To: Dave Taht Content-Type: multipart/alternative; boundary=bcaec51967493083e804cf679375 Cc: cerowrt-users@lists.bufferbloat.net, Marc MERLIN , cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] [Cerowrt-users] QOS settings vs speedboost and random bandwidth X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Nov 2012 15:27:47 -0000 --bcaec51967493083e804cf679375 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Mon, Nov 26, 2012 at 3:32 AM, Dave Taht wrote: > there are not presently a lot of cerowrt-users members, so I'm cc-ing > cerowrt-devel. > > On Mon, Nov 26, 2012 at 12:20 AM, Marc MERLIN wrote: > > I'm setting up QOS as explained in the FAQ > > http://www.bufferbloat.net/projects/cerowrt/wiki/FAQ > > > > > > Not surprisingly > > speednest.net > > gives me 33Mbit/7.65Mbit while dslreports.com/speedtest > > gives > > me a meager 16.2Mbit/2.5Mbit (for a line that's supposed to be > 22Mbit/5Mbit). > > Yes, you get a boost for about 10 seconds. > > > I understand the queuing and that if I put too high a number, I'll fill > > queues and end up with bad latency. > > yep. > > > > > At the same time, am I correct that if I put numbers that are lower tha= n > > what I can really get when the line doesn't suck, I'll cap myself to > those > > numbers (here 16.2Mbit instead of 22Mbit or so)? > > > yep. > > > > > Is it also possible for linux/cerowrt to dynmically detect the > queuing/delay > > in my cable modem and dynamically adjust the QOS values to limit > buffering > > on the comcast side without throttling me down to lower than what the > line > > can do at any given time? > > Nope. The right answer is to not have to rate shape in the router, but > to move the fq_codel algorithm into the cable modem, OR to have the > cable modem exert flow control like ADSL modems do. Then have the > smarter device (the router) then do smarter queuing. > > There are other dynamic bandwidth effects on a cable network that > result in more widely varying backend bandwidth. > Yes, and under conditions of overall network congestion, if you are using your link at a high fraction (> 80% or so, IIRC), they may also take some action after an extended period (something like 10-15 minutes), as part of their protocol neutral congestion management system. There are also physical effects (temperature) that can cause some bandwidth variation. > > A little birdie tells me that the cable modem guys are on this... > speedboost is a good idea but the only way to not lose it is to move > the smarts around. > Yup. It's a good feature and it's sad to have to defeat it (unless someone does a Powerboost emulator). > > That said, it does seem possible to develop a speedboost emulator on > the router that would give you most of the benefit. > The details of at least Comcast's "Powerboost" may be documented in the RFC published describing their provisioning. I don't have the RFC handy. I think the algorithm they use is described there, even if the exact parameters for a particular provisioning tier is not... > > > > > > I'm also a bit concerned of what happens when comcasts ups my bandwidth > > without telling me (they do that sometimes) and me never finding out if= I > > have a static QOS value in cerowrt. > They certainly tell you in the advertising spam that we all delete ;-(. - Jim > > > > Can others advise? > > > > Thanks, > > Marc > > -- > > "A mouse is a device used to point at the xterm you want to type in" - > A.S.R. > > Microsoft is to operating systems .... > > .... what McDonalds is to gourmet > cooking > > Home page: http://marc.merlins.org/ > > > > _______________________________________________ > > Cerowrt-users mailing list > > Cerowrt-users@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/cerowrt-users > > > > > > -- > Dave T=E4ht > > Fixing bufferbloat with cerowrt: > http://www.teklibre.com/cerowrt/subscribe.html > > > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel > > > --bcaec51967493083e804cf679375 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable


On Mon, N= ov 26, 2012 at 3:32 AM, Dave Taht <dave.taht@gmail.com> wr= ote:
there are not presently a lot of cerowrt-use= rs members, so I'm cc-ing
cerowrt-devel.

On Mon, Nov 26, 2012 at 12:20 AM, Marc MERLIN <marc@merlins.org> wrote:
> I'm setting up QOS as explained in the FAQ
> http://www.bufferbloat.net/projects/cerowrt/wiki/FAQ
=A0

>
> Not surprisingly
> speednest.net=A0
gives me= 33Mbit/7.65Mbit while dslreports.com/speedtest
=A0
gives
> me a meager 16.2Mbit/2.5Mbit (for a line that's supposed to be 22M= bit/5Mbit).

Yes, you get a boost for about 10 seconds.

> I understand the queuing and that if I put too high a number, I'll= fill
> queues and end up with bad latency.

yep.

>
> At the same time, am I correct that if I put numbers that are lower th= an
> what I can really get when the line doesn't suck, I'll cap mys= elf to those
> numbers (here 16.2Mbit instead of 22Mbit or so)?


yep.

>
> Is it also possible for linux/cerowrt to dynmically detect the queuing= /delay
> in my cable modem and dynamically adjust the QOS values to limit buffe= ring
> on the comcast side without throttling me down to lower than what the = line
> can do at any given time?

Nope. The right answer is to not have to rate shape in the router, but
to move the fq_codel algorithm into the cable modem, OR to have the
cable modem exert flow control like ADSL modems do. Then have the
smarter device (the router) then do smarter queuing.

There are other dynamic bandwidth effects on a cable network that
result in more widely varying backend bandwidth.

<= /div>
Yes, and under conditions of overall network congestion, if you a= re using your link at a high fraction (> 80% or so, IIRC), they may also= take some action after an extended period (something like 10-15 minutes), = as part of their protocol neutral congestion management system.

There are also physical effects (temperature) that can = cause some bandwidth variation.
=A0

A little birdie tells me that the cable modem guys are on this...
speedboost is a good idea but the only way to not lose it is to move
the smarts around.

Yup. =A0It's a g= ood feature and it's sad to have to defeat it (unless someone does a Po= werboost emulator).=A0

That said, it does seem possible to develop a speedboost emulator on
the router that would give you most of the benefit.
The details of at least Comcast's "Powerboost" m= ay be documented in the RFC published describing their provisioning. =A0 I = don't have the RFC handy. =A0I think the algorithm they use is describe= d there, even if the exact parameters for a particular provisioning tier is= not...


>
> I'm also a bit concerned of what happens when comcasts ups my band= width
> without telling me (they do that sometimes) and me never finding out i= f I
> have a static QOS value in cerowrt.

They certainly tell you in the advertising spam that we all delete ;-(.
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0- Jim
=A0
>
> Can others advise?
>
> Thanks,
> Marc
> --
> "A mouse is a device used to point at the xterm you want to type = in" - A.S.R.
> Microsoft is to operating systems ....
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0 .... what McDonalds is to gourmet cooking
> Home page: http= ://marc.merlins.org/
=A0

> _______________________________________________
> Cerowrt-users mailing list
> Cerowrt-users@l= ists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-users
=A0




--
Dave T=E4ht

Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscrib= e.html
=A0
_______________________________________________
Cerowrt-devel mailing list
Cerowrt-devel@lists.= bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel
=A0


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