From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com [IPv6:2a00:1450:4864:20::22c]) (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 62F8A3CB39 for ; Mon, 14 Jan 2019 17:10:35 -0500 (EST) Received: by mail-lj1-x22c.google.com with SMTP id v1-v6so599054ljd.0 for ; Mon, 14 Jan 2019 14:10:35 -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=C1gpuDIdDOlt02UMqvPnYf5Xh3APBLGTCGVND+DA838=; b=eLMSOC03lzo0orHs1+A8n32TteXmlICdWLg7ZBq93LuAilQwueVmwI4Rr6Xo2gXOme X3+69E/hiuGob6fJOZJcan/0MUW0Cjo5fcYS0u13e2lhrTpXwWczxlUZmJI/bp6uCjLT ctlmnkN7FLWHmWnVcv1VYA4IuMW+Jj2O+MHYO126ekx6bdP/UKSOAuFaOEppvEnNuyRv Xoa7AC8K5paGXMP/+7nn9ZyaRGkLnDOY66vdwVQ2xR8zNIQRq8aq9R56aoZECVNtL5xy JIFmiqJghpjXKAx7O6hbZPn4VOp2PWuKf3LPPiYZFkFOddXsuJ6CtJsgW/sjYYjVMpNa 2Nzw== 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=C1gpuDIdDOlt02UMqvPnYf5Xh3APBLGTCGVND+DA838=; b=S0nis6uutZBEoOG2qV39G1oug27wMSCfTMMwsPXuC6ahljvePyg/XJanBCspIwzL8C wrLm4BGt7iOUbIbSfqzNK4/aiYRPbwYLt+VdqhU10EfRDrCUTOfmHpCfCgKJWzNj/+sz 6e6c04j8prCMtfFfTsOJtONBXBtK8ZZpcjZy8YEMtc28g4yC1RzTIzUSp6fWggj7sZAw lt/ydQmlRRhrhoBMhbgOt4+/191bapKJSw/rKItmtLOVQaJSdrYBbDAUCxt7oiNEIkLI OdDZF22rVUFpJxK0AH5VLCfSn/B8Ir+bFxmVsBuKpONOAzgiIDs7L5GOtoCjsywTKucw aGZg== X-Gm-Message-State: AJcUukdA1bT+thhu+eQDwXk1QccyF3/Ky/wfVZn+WMVW003MNXjsKH7Q 2dn/AKLH54mjU1jbBnAmFjD2pG7Mg6PCjWt0hX0= X-Google-Smtp-Source: ALg8bN4XqlEDS/mnAeYzTP+dJcjn7IzWQ6+bN316hPTvKCTFwgKIfHR9BEbMlF06btvHdYq8Dc9yG0ZFYyHo0HtYnCA= X-Received: by 2002:a2e:2416:: with SMTP id k22-v6mr505199ljk.80.1547503834009; Mon, 14 Jan 2019 14:10:34 -0800 (PST) MIME-Version: 1.0 References: <4D6E822B-A866-4513-90CF-93C6E6308F41@gmail.com> <9B8E2B07-BBDB-41A4-BA21-AB9B4CEFE075@gmail.com> In-Reply-To: <9B8E2B07-BBDB-41A4-BA21-AB9B4CEFE075@gmail.com> From: Rodrigo Alvarez Dominguez Date: Mon, 14 Jan 2019 23:10:23 +0100 Message-ID: To: Jonathan Morton Cc: codel@lists.bufferbloat.net Content-Type: multipart/alternative; boundary="0000000000005095a8057f7250ba" Subject: Re: [Codel] Codel configuration X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Jan 2019 22:10:35 -0000 --0000000000005095a8057f7250ba Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Thanks for the tip! I will try with your numbers. Really appreciate your help. I will check later with cake. Is cake autotuning the target and interval? Regards, Rodrigo El lun., 14 ene. 2019 a las 17:48, Jonathan Morton (= ) escribi=C3=B3: > > On 14 Jan, 2019, at 6:17 pm, Rodrigo Alvarez Dominguez < > rodroleon@gmail.com> wrote: > > > > Hi Jonathan > > Thanks for your quick answer. REally appreciate it!!! > > I wil try later the cake statement (is it the same as codel)?. I am > starting with Codel. So I need to have a better understanding of codel. > > Cake is a more advanced implementation of the same principles. Its shape= r > is more accurate than HTB, and it's easier to configure correctly than th= e > component qdiscs and filters you're currently using. > > > Where client asks for a FTP file to server. Link between router-server > has a 150MBit speed with a delay of 250 ms. > > Then link between client and router has 10 Mbit and the Codel algorithm= . > So I am checking the differences between having codel or not. > > Do you have an advice to have a good scenario for testing Codel > properly? Or a document to know how the differences parameter can affect = to > the communication? > > In my scenario it seems it is better not having Codel. See attached > ClientFTPCodelNO-NO-NO (nocodel) versus ClientFtpCodel1000.. > > where a Codel Algorithm of 1000 packets, 13 ms target and 100 interval > is configured > > First, and most importantly, you're measuring only throughput, while > ignoring latency. The primary benefit of any 'smart queue" is in reducin= g > latency, preferably with the least practical impact on throughput. Dumb > FIFOs often induce latencies of several seconds when loaded. The > improvement is visible to the user as quicker response and better > reliability of operation while the link is busy. Here's a better test to > try out: > > http://www.dslreports.com/speedtest > > Second, your Codel parameters are too tight for the relatively > long-latency path you're measuring. You should set "interval" to your > expected path latency (250ms) and "target" to about a tenth of that > (25ms). I would also advise against "noecn" and replace it with "ecn"; > this will safely have no effect if you don't have ECN-enabled traffic, bu= t > reduces packet loss if you do. > > Cake has an "rtt" parameter so you don't have to manually select a target > and interval, and it unconditionally supports ECN. Updating my earlier > suggestion: > > tc qdisc replace dev r1-eth0 root handle 1: cake bandwidth > 10000kbit besteffort flows rtt 250ms > > Third, you should turn on ECN on your end-hosts if you can. Most servers > will respond with ECN traffic if requested, so search for instructions fo= r > enabling ECN on your own machine. > > - Jonathan Morton > > --0000000000005095a8057f7250ba Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thanks for the tip! I will try with your numbers. Really a= ppreciate your help.=C2=A0
I will check later with cake. Is cake au= totuning the target and interval?
Regards,
Rodrigo

El lun., 14 ene. 201= 9 a las 17:48, Jonathan Morton (<chromatix99@gmail.com>) escribi=C3=B3:
> On 14 Jan, 2019, at 6:17 pm, Rodrigo = Alvarez Dominguez <rodroleon@gmail.com> wrote:
>
> Hi Jonathan
> Thanks for your quick answer. REally appreciate it!!!
> I wil try later the cake statement (is it the same as codel)?. I am st= arting with Codel. So I need to have a better understanding of codel.

Cake is a more advanced implementation of the same principles.=C2=A0 Its sh= aper is more accurate than HTB, and it's easier to configure correctly = than the component qdiscs and filters you're currently using.

> Where client asks for a FTP file to server. Link between router-server= has a 150MBit speed with a delay of 250 ms.
> Then link between client and router has 10 Mbit and the Codel algorith= m. So I am checking the differences between having codel or not.
> Do you have an advice to have a good scenario for testing Codel proper= ly? Or a document to know how the differences parameter can affect to the c= ommunication?
> In my scenario it seems it is better not having Codel.=C2=A0 See attac= hed ClientFTPCodelNO-NO-NO (nocodel) versus ClientFtpCodel1000..
> where a Codel Algorithm of 1000 packets, 13 ms target and 100 interval= is configured

First, and most importantly, you're measuring only throughput, while ig= noring latency.=C2=A0 The primary benefit of any 'smart queue" is = in reducing latency, preferably with the least practical impact on throughp= ut.=C2=A0 Dumb FIFOs often induce latencies of several seconds when loaded.= =C2=A0 The improvement is visible to the user as quicker response and bette= r reliability of operation while the link is busy.=C2=A0 Here's a bette= r test to try out:

=C2=A0 =C2=A0 =C2=A0 =C2=A0 http://www.dslreports.com/speedtest

Second, your Codel parameters are too tight for the relatively long-latency= path you're measuring.=C2=A0 You should set "interval" to yo= ur expected path latency (250ms) and "target" to about a tenth of= that (25ms).=C2=A0 I would also advise against "noecn" and repla= ce it with "ecn"; this will safely have no effect if you don'= t have ECN-enabled traffic, but reduces packet loss if you do.

Cake has an "rtt" parameter so you don't have to manually sel= ect a target and interval, and it unconditionally supports ECN.=C2=A0 Updat= ing my earlier suggestion:

=C2=A0 =C2=A0 =C2=A0 =C2=A0 tc qdisc replace dev r1-eth0 root handle 1: cak= e bandwidth 10000kbit besteffort flows rtt 250ms

Third, you should turn on ECN on your end-hosts if you can.=C2=A0 Most serv= ers will respond with ECN traffic if requested, so search for instructions = for enabling ECN on your own machine.

=C2=A0- Jonathan Morton

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