From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x82a.google.com (mail-qt1-x82a.google.com [IPv6:2607:f8b0:4864:20::82a]) (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 AC7773B2A4 for ; Thu, 29 Nov 2018 03:09:14 -0500 (EST) Received: by mail-qt1-x82a.google.com with SMTP id l11so1056985qtp.0 for ; Thu, 29 Nov 2018 00:09:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PmO+xsiCzh1fnLWeGXE1whj04WQsoizm2Iw9JmKv0Ic=; b=pfFdJsqyo6UpXL2jWySDMqgF2ox2a5VR8rfNZOaJOAdQ44NKkVcNyyO2fNhI06+ZFm Vp3ERnpxp++ZIcwY1bcbj+b3sCtkD9mwecIpxzHHmresQzrsorrFTTFArrXsfM7cfiHo kipsUU+13D+8t8bWmz1wHocwaLiRM3ISXolK94siXjSJHX/7AS6l6MczHwKvvaLzvucZ pHm+coTlhE260MuSGX82Jh4w8GJZvYVZplbQOeAp8UAHnHXG7Hk7ZVg/g167hwcECDdB m0an9hW4ouswSEgjIrBw+xt+2lvDpDZ3Gh1XLh6FXkdnh0yysGWEij2BwZqoFcewCtJV hmVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PmO+xsiCzh1fnLWeGXE1whj04WQsoizm2Iw9JmKv0Ic=; b=kW2W6aY9JQdW9TzdDHeKPtZLlCtHR9y9ZmZaQI7Pi1CPZRb925lWj44KDGGV7ePpfE IGK+k/UFbptbjurwNRY0a3zh9HcA+reh1TmM2ssys4w14OxiPf6rTC9qDhheeikf2CRw xNx2JHmYtGXteEWNZQa+/vW9Hf7xwhjzjdvnHU9osSZO0L8YMqEItW/xstLhdiOgnm11 k3Zl3qqFy2WLHB97qeSU+7xxlLhPtMnBm0rnAOXEwEPdaKm4UyUq468iA+r62Si2xsdb vxuOaIB0pIX3HeP9DFvAX2J/G8CMOVWN2qePIHkxpIXeWMztj4CkkDreTfzJFzgWugAL AX+w== X-Gm-Message-State: AA+aEWa5ZPjyX3PV5rhY2SLNfAg/8uML/lE3C2fnDoN7mVEBvFXcfdxt Ng+dMnh2ocqV/XMpsVGvMLLOgpjqa3Ee2BfaAS0= X-Google-Smtp-Source: AFSGD/WfsyE5ue6XnM8FOAvrn/MVJ/bbZERbdTkQXLeiVSSwhnqzvM5qZWfj/TDuOg21nehxBZ8NKdPBGwcHOMyQo4g= X-Received: by 2002:aed:2946:: with SMTP id s64mr412962qtd.383.1543478954147; Thu, 29 Nov 2018 00:09:14 -0800 (PST) MIME-Version: 1.0 References: <65EAC6C1-4688-46B6-A575-A6C7F2C066C5@heistp.net> <86b16a95-e47d-896b-9d43-69c65c52afc7@kit.edu> <7e6cc6f4-bd2f-49b5-0f64-292f56a0592c@kit.edu> <878t1cwcvn.fsf@taht.net> In-Reply-To: From: Luca Muscariello Date: Thu, 29 Nov 2018 09:09:02 +0100 Message-ID: To: Dave Taht Cc: Jonathan Morton , bloat Content-Type: multipart/alternative; boundary="000000000000c7c30b057bc93282" Subject: Re: [Bloat] when does the CoDel part of fq_codel help in the real world? 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: Thu, 29 Nov 2018 08:09:14 -0000 --000000000000c7c30b057bc93282 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable If you have multiple flows the BDP will change as measured at the end points. Also the queue occupancy has to accommodate the overshoot. If you have a BDP in flight plus epsilon you should not size based on the long term value but on the overshoot. If you don't have space for it, the long term value may be even larger. On Thu, Nov 29, 2018 at 8:55 AM Dave Taht wrote: > On Wed, Nov 28, 2018 at 11:45 PM Jonathan Morton > wrote: > > > > > On 29 Nov, 2018, at 9:39 am, Dave Taht wrote: > > > > > > =E2=80=A6when it is nearly certain that more than one flow exists, me= ans aiming > > > for the BDP in a single flow is generally foolish. > > > > It might be more accurate to say that the BDP of the fair-share of the > path is the cwnd to aim for. Plus epsilon for probing. > > OK, much better, thanks. > > > - Jonathan Morton > > > > _______________________________________________ > > Bloat mailing list > > Bloat@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/bloat > > > > -- > > Dave T=C3=A4ht > CTO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-831-205-9740 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --000000000000c7c30b057bc93282 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
If you have multiple flows the BDP will change as measured= at the end points.
Also the queue occupancy has to accommodate the ove= rshoot. If you have a BDP in flight plus=C2=A0
epsilon you should= not size based on the long term value but on the overshoot.=C2=A0
If you don't have space for it, the long term value may be even large= r.=C2=A0

On Thu,= Nov 29, 2018 at 8:55 AM Dave Taht <dave.taht@gmail.com> wrote:
On Wed, Nov 28, 2018 at 11:45 PM Jonathan Morton <chromatix99@gmail.com> wrote= :
>
> > On 29 Nov, 2018, at 9:39 am, Dave Taht <dave@taht.net> wrote:
> >
> > =E2=80=A6when it is nearly certain that more than one flow exists= , means aiming
> > for the BDP in a single flow is generally foolish.
>
> It might be more accurate to say that the BDP of the fair-share of the= path is the cwnd to aim for.=C2=A0 Plus epsilon for probing.

OK, much better, thanks.

>=C2=A0 - Jonathan Morton
>
> _______________________________________________
> Bloat mailing list
> Bloat= @lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/bloat


--

Dave T=C3=A4ht
CTO, TekLibre, LLC
ht= tp://www.teklibre.com
Tel: 1-831-205-9740
_______________________________________________
Bloat mailing list
Bloat@list= s.bufferbloat.net
https://lists.bufferbloat.net/listinfo/bloat
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