From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) (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 0EE3D201AF7 for ; Mon, 7 May 2012 13:03:45 -0700 (PDT) Received: by eekc13 with SMTP id c13so2165741eek.16 for ; Mon, 07 May 2012 13:03:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; bh=lhwaPwZx2FCbsi1SVOo870mPYFOwQHYM7hoOrVLNn9Y=; b=C09iArFEDwf2Y0X8HjoTeXfv0mQ74cOR7fBKd6PKX/nzQ+Wz8kfG1E/CG1nOl7B99z 4/Vr1oa0+BRBTaWZHJEkwRzDE+VcSvNegzqQrjyHlCXAUjiSxL8ZjSoKa6EDBCtZeNr7 ZziVCpV9ht8aMzMEyFIwO1FEy0vRyb0FoTaHmUS46+B9i1oXSwPs63+xOgt7bL7PjJal rfJIlXv/j3H7j627vC3Dkpl67aMY2Rb5m49CoFaF8E0Ya0qDEnz1BFDvoTt9uBJrgkP5 8PfPrE6iLEHhn+wXGRo+R0yvuM2D3jq1JMGG/37x6ehA6cXYmzYlLXwVr3FPtFA7KKV7 hGIg== Received: by 10.213.33.193 with SMTP id i1mr1222175ebd.45.1336421023732; Mon, 07 May 2012 13:03:43 -0700 (PDT) Received: from [192.168.163.193] ([74.125.121.33]) by mx.google.com with ESMTPS id p57sm91204935eei.8.2012.05.07.13.03.41 (version=SSLv3 cipher=OTHER); Mon, 07 May 2012 13:03:42 -0700 (PDT) From: Eric Dumazet To: Jim Gettys In-Reply-To: <4FA82422.9040500@freedesktop.org> References: <1336246349-20228-1-git-send-email-dave.taht@bufferbloat.net> <4FA7FBC7.2040501@hp.com> <1336410626.3752.2329.camel@edumazet-glaptop> <4FA805F9.20004@hp.com> <1336412079.3752.2333.camel@edumazet-glaptop> <4FA81549.5060609@freedesktop.org> <4FA8197C.4090909@freedesktop.org> <1336418211.3752.2353.camel@edumazet-glaptop> <4FA82422.9040500@freedesktop.org> Content-Type: text/plain; charset="UTF-8" Date: Mon, 07 May 2012 22:03:40 +0200 Message-ID: <1336421020.3752.2359.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , codel@lists.bufferbloat.net, Dave Taht Subject: Re: [Codel] [PATCH 1/2] codel: Controlled Delay AQM X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 May 2012 20:03:46 -0000 On Mon, 2012-05-07 at 15:36 -0400, Jim Gettys wrote: > I think it is safe for it to behave the rest of the way Linux ECN > support does right now: it only gets used if the peer requests it. > > Not clear to me there needs to be/should be any option at all: the last > conversation I had with Steve Bauer was that something north of 20% of > conversations were ECN capable. Is there one for the other instances of > ECN support in Linux? If so, it should be keyed by the same variable, > and not be a one-off for codel. > SFB, one of the latest qdisc added in linux has ECN support enabled. There is no option to disable it, because I felt it was safe. Maybe I was a fool, but problem is I am not sure SFB is even used. > If you wanted to test ECN separately from drop with codel, then you'd > just request ECN in the conversation (by default, OS's don't normally > request ECN today, as the remaining brokenness gets sorted out). Since ECN is not mentioned in Codel paper, this means no simulation was done to study the possible effects. So its probably better to leave ECN as an option. We can change the default later.