From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) (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 8562D3B2A4 for ; Wed, 9 Mar 2022 12:51:49 -0500 (EST) Received: by mail-pf1-x429.google.com with SMTP id t5so2963207pfg.4 for ; Wed, 09 Mar 2022 09:51:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OvKBCR+JDFjOAWyhCYeHGVT0QoM/FBnRYOA9z+AMuMw=; b=jCGoYApGSAjrIQp3mE7aSV4jq+g6kJNv7z5oZB2yBCRacAeW42qX+iYmfh8dNG8faQ EuaAvIBcmWMbG7xdhygCJO2O2XLY378jRIZkHQod/wApPuTg5/xzl0k5mQPK1w/gUl0A vCve9JMEA5McEcltiv2tV2V4c7l6pTKBqm6Se+ng+w753ZJUqqnLViK1Y6NTtWkfADoZ TTX4uTRAM1bki+7wt9yG2LmycFBtXbVC6iu+8bdMddc5Xhx8K4NGT2yfIc6tojTwhT0Y iVOv62W6+rcueL0HpCaIJvxwmBGMfyKDbdod6VaHDOrM9zE/Zcy161ZjAT5jzIZqWtjj dNbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=OvKBCR+JDFjOAWyhCYeHGVT0QoM/FBnRYOA9z+AMuMw=; b=1UDUf7iwCCyrkoaPHo8D0W4q6L7Hfe8Mt1DT2hNhs9WimTjyhmNIWVCgJL4PpTuqOP av3XaHa1xwuZstRdctiNUHxFm48nK2tTmtPtmv80mF/0o+1LB2WPf0iRpYrl5osNX0v9 1+B4OAM9QyuFgeG1zQZ8w2Mq/hktoOCcea5QykSEZmlSoZuIMGclVY9q995E0Qcs4wH9 F18I1bC8aDXOEjv07SbDkpBzch7DBHQzIx7Br3EXb6u5y7SlTyAjypvSIlL+pazGklhz NvRgd32Mgav4KiLKCr8aqtPjSNQWiW0CbQU9ioTJvxL90N69n/Cn9Sml+I38kPNzZOYm Ul5g== X-Gm-Message-State: AOAM530OqojTztpMaBVvprcpe2j4fPFhr8C32EK5A0ubs5828rPr9GnA LAeybrYd3x4A+54o8GCaeHKd8bPcpq1iYetX+/M= X-Google-Smtp-Source: ABdhPJwSfv7uRHHYFIUNcNkglw72x1wvoTKG0sptORz1hE0EHwsu2KPHhoaUxlCwl827Fx2J9/pEFWF+otgMVaD6Okg= X-Received: by 2002:a63:87c2:0:b0:380:93c6:e29a with SMTP id i185-20020a6387c2000000b0038093c6e29amr715765pge.310.1646848308378; Wed, 09 Mar 2022 09:51:48 -0800 (PST) MIME-Version: 1.0 References: <87y21julxu.fsf@toke.dk> <9785d2cd-b164-deb4-4cbe-7d0fb356f16e@redhat.com> <5a8b6b4a-7f15-3f08-56b5-9e04773271bb@uni-tuebingen.de> In-Reply-To: <5a8b6b4a-7f15-3f08-56b5-9e04773271bb@uni-tuebingen.de> From: Aaron Wood Date: Wed, 9 Mar 2022 09:51:36 -0800 Message-ID: To: Michael Menth Cc: Jesper Dangaard Brouer , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , bloat Content-Type: multipart/alternative; boundary="0000000000006b7fed05d9ccc0d3" Subject: Re: [Bloat] Up-to-date buffer sizes? 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, 09 Mar 2022 17:51:49 -0000 --0000000000006b7fed05d9ccc0d3 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Are you asking what they _should_ be, or what the typical buffering seen in equipment actually is? On Wed, Mar 9, 2022 at 9:39 AM Michael Menth wrote= : > Hi all, > > I don't question the usefulness of AQMs for buffers - on the contrary. > But what are up-to-date buffer sizes in networking gears, especially if > AQMs are not in use? It's hard to find public and information about it. > Anyone can point to a citable source? > > This raises also the question about the deployment of AQMs in networking > infrastructure. I know it's already adopted by some OSs, but what about > forwarding nodes? Any papers about it? > > Kind regards > > Michael > > Am 09.03.2022 um 18:24 schrieb Jesper Dangaard Brouer: > > > > > > On 09/03/2022 17.31, Toke H=C3=B8iland-J=C3=B8rgensen via Bloat wrote: > >> Michael Menth writes: > >> > >>> Hi all, > >>> > >>> are there up-to-date references giving evidence about typical buffer > >>> sizes for various link speeds and technologies? > >> > >> Heh. There was a whole workshop on it a couple of years ago; not sure = if > >> it concluded anything: http://buffer-workshop.stanford.edu/program/ > >> > >> But really, asking about buffer sizing is missing the point; if you ha= ve > >> static buffers with no other management (like AQM and FQ) you're most > >> likely already doing it wrong... :) > > > > Exactly, I agree with Toke. The important parameter is the latency. > > Or the packet sojourn time (rfc8289 + rfc8290) observed waiting in the > > queue. > > > > The question you should be asking is: > > - What is the max queue latency I'm "willing" to experience on this > link? > > > > Hint, you can then depending on the link rate calculate the max buffer > > size you should configure. > > > > The short solution is: > > - just use fq_codel (rfc8290) as the default qdisc. > > > > --Jesper > > > > > > > > -- > Prof. Dr. habil. Michael Menth > University of Tuebingen > Faculty of Science > Department of Computer Science > Chair of Communication Networks > Sand 13, 72076 Tuebingen, Germany > phone: (+49)-7071/29-70505 > fax: (+49)-7071/29-5220 > mailto:menth@uni-tuebingen.de > http://kn.inf.uni-tuebingen.de > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --=20 - Sent from my iPhone. --0000000000006b7fed05d9ccc0d3 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Are you asking what they _should_ be, or what the typical= buffering seen in equipment actually is?

=

O= n Wed, Mar 9, 2022 at 9:39 AM Michael Menth <menth@uni-tuebingen.de> wrote:
Hi all,

I don't question the usefulness of AQMs for buffers - on the contrary. =
But what are up-to-date buffer sizes in networking gears, especially if AQMs are not in use? It's hard to find public and information about it.=
Anyone can point to a citable source?

This raises also the question about the deployment of AQMs in networking infrastructure. I know it's already adopted by some OSs, but what about=
forwarding nodes? Any papers about it?

Kind regards

Michael

Am 09.03.2022 um 18:24 schrieb Jesper Dangaard Brouer:
>
>
> On 09/03/2022 17.31, Toke H=C3=B8iland-J=C3=B8rgensen via Bloat wrote:=
>> Michael Menth <menth@uni-tuebingen.de> writes:
>>
>>> Hi all,
>>>
>>> are there up-to-date references giving evidence about typical = buffer
>>> sizes for various link speeds and technologies?
>>
>> Heh. There was a whole workshop on it a couple of years ago; not s= ure if
>> it concluded anything: http://buffer-workshop.s= tanford.edu/program/
>>
>> But really, asking about buffer sizing is missing the point; if yo= u have
>> static buffers with no other management (like AQM and FQ) you'= re most
>> likely already doing it wrong... :)
>
> Exactly, I agree with Toke. The important parameter is the latency. > Or the packet sojourn time (rfc8289 + rfc8290) observed waiting in the=
> queue.
>
> The question you should be asking is:
>=C2=A0 =C2=A0- What is the max queue latency I'm "willing"= ; to experience on this link?
>
> Hint, you can then depending on the link rate calculate the max buffer=
> size you should configure.
>
> The short solution is:
>=C2=A0 =C2=A0- just use fq_codel (rfc8290) as the default qdisc.
>
> --Jesper
>
>
>

--
Prof. Dr. habil. Michael Menth
University of Tuebingen
Faculty of Science
Department of Computer Science
Chair of Communication Networks
Sand 13, 72076 Tuebingen, Germany
phone: (+49)-7071/29-70505
fax: (+49)-7071/29-5220
mailto:menth@un= i-tuebingen.de
http://kn.inf.uni-tuebingen.de
_______________________________________________
Bloat mailing list
Bloat@list= s.bufferbloat.net
https://lists.bufferbloat.net/listinfo/bloat
--
- Sent from my iPhone.
--0000000000006b7fed05d9ccc0d3--