From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f47.google.com (mail-wg0-f47.google.com [74.125.82.47]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 467CC2008E8 for ; Mon, 25 Jun 2012 10:48:26 -0700 (PDT) Received: by wgbfa7 with SMTP id fa7so3125419wgb.28 for ; Mon, 25 Jun 2012 10:48:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=references:in-reply-to:mime-version:content-transfer-encoding :content-type:message-id:cc:x-mailer:from:subject:date:to; bh=OcQOMcW0oCwbHKO7Lst4ZL4bxTeor3GW5N8jEePA+rs=; b=gs6zb34bqIX8+SZqLCsbckwzsfwoNC6BGa/ZWGMdCN9P8+YaIzQrEYIzIkUJRMpabk A8EOsqBM5MA6kyilo/bMeqglCZv+4UBvvZzkYEYjFfVodAQB7vdxwQ4lCUMhhUob/V6i fnpV6ufPs+C5d7ndT0Y8HLyZNHT5zpJb+khGeMtB5XMAjOwtvNZEsTC9ung3i3RI3+9+ e/Cfe3S9VZM3hEiDd6jtQnc/+C640r8OpQFo8IsLB12wqZmTfWxM6GZFhHX1eSgzgxAH dz//vKg8mqeQpWKGWpGp200rB8Qv3dW8sK/Pc61DFC8UD/IqMxA7Ce3cq9me0C7hvJP4 AD7w== Received: by 10.216.210.229 with SMTP id u79mr7317964weo.31.1340646505168; Mon, 25 Jun 2012 10:48:25 -0700 (PDT) Received: from [192.168.239.203] (xdsl-83-150-84-172.nebulazone.fi. [83.150.84.172]) by mx.google.com with ESMTPS id z8sm35895479wiy.1.2012.06.25.10.48.23 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 25 Jun 2012 10:48:24 -0700 (PDT) References: <1340600422-1806-1-git-send-email-dave.taht@bufferbloat.net> <1340600422-1806-2-git-send-email-dave.taht@bufferbloat.net> <1340601724.23933.16.camel@edumazet-glaptop> <1340637617.10893.56.camel@edumazet-glaptop> <1340639151.10893.79.camel@edumazet-glaptop> In-Reply-To: <1340639151.10893.79.camel@edumazet-glaptop> Mime-Version: 1.0 (iPhone Mail 8C148) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Message-Id: <5AD96B37-CDEE-44B6-83CC-449C27FCBA76@gmail.com> X-Mailer: iPhone Mail (8C148) From: Jonathan Morton Date: Mon, 25 Jun 2012 20:48:51 +0300 To: Eric Dumazet Cc: "codel@lists.bufferbloat.net" , =?utf-8?Q?Dave_T=C3=A4ht?= Subject: Re: [Codel] [RFCv2 PATCH] codel: add ecn_target for when to drop rather than mark ecn packets 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, 25 Jun 2012 17:48:28 -0000 My impression is that ECN ignorant flows do exist, because of stupid routers= rather than malice, and that Dave considers this a problem worth tackling i= n codel.=20 However I would disagree that the problem needs tackling here, at least for f= q_codel which already segregates non-responsive flows from others. The ignor= ant flows will experience higher latency if this link is a bottleneck for th= em, that is all.=20 Plain codel might need a more robust defence, but I have a different suggest= ion for that. Determine whether a prolonged bout of marking is being caused b= y ECN ignorant flows, and if so disable ECN marking (just drop) until the ig= norant flows have clearly gone away.=20 The key to knowledge is not to rely on others to teach you it.=20 On 25 Jun 2012, at 18:45, Eric Dumazet wrote: > On Mon, 2012-06-25 at 08:30 -0700, Dave Taht wrote: >=20 >> It was the way I was leaning until I observed me dropping ecn enabled >> mosh, ssh, and babel packets , which tend to be small, so I started >> thinking in terms of dropping ecn packets on a graduated packet size >> scale after exceeding target. ESPECIALLY in case of overload you want >> command and control packets to get through. >>=20 >=20 > Don't try to add in CoDel things that should be done at another layer. > There is no classification in CoDel : Its a FIFO. >=20 > Only way is to prioritize control packets if you need to, and use > several queues. >=20 > I dont understand... Are you saying that you feel the need to drop > packets instead of marking them in a 'good citizen world' (none of your > flow pretends to use ECN to avoid drops) ? >=20 >=20 >=20 > _______________________________________________ > Codel mailing list > Codel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/codel