From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1.sandvine.com (Mail1.sandvine.com [64.7.137.134]) by huchra.bufferbloat.net (Postfix) with ESMTP id 08F1F21F231; Mon, 2 Mar 2015 02:47:10 -0800 (PST) Received: from WTL-EXCHP-2.sandvine.com ([fe80::68ac:f071:19ff:3455]) by wtl-exchp-1.sandvine.com ([fe80::ac6b:cc1e:f2ff:93aa%18]) with mapi id 14.03.0195.001; Mon, 2 Mar 2015 05:47:09 -0500 From: Dave Dolson To: "'dave.taht@gmail.com'" , "'cerowrt-devel@lists.bufferbloat.net'" , "'aqm@ietf.org'" , "'bloat@lists.bufferbloat.net'" Thread-Topic: [aqm] ping loss "considered harmful" Thread-Index: AQHQVJ0J+9InyssQxUGw8Kj3YWubiJ0JAzt7 Date: Mon, 2 Mar 2015 10:47:07 +0000 Message-ID: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [192.168.194.115] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 02 Mar 2015 06:55:41 -0800 Subject: Re: [Cerowrt-devel] [aqm] ping loss "considered harmful" X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Mar 2015 10:47:39 -0000 I'm rather new to the aqm community, but IMHO, it is wrong to deprioritize = the ping traffic by default. I would not have expected a forwarding agent t= o do this.=20 And I think measuring ping times and loss is a reasonable thing to do, neve= r expecting forwarding agents along the path to place more value on some IP= packets than others. (Especially in my own network/lab when I did not conf= igure such a policy) There aren't many tools available to an end user. Ping, traceroute, speed t= est... The network is a black box to most users.=20 As for the flood attack aspect, of course a flood of pings should wait thei= r turn in a queue and be dropped as the queue fills. It would be appropriate if this was fair to different ping flows in the sam= e way TCP SYN packets are treated fairly. Treat ping flood like TCP SYN flo= od. =20 My 2cents.=20 -Dave Dolson ----- Original Message ----- From: Dave Taht [mailto:dave.taht@gmail.com] Sent: Sunday, March 01, 2015 10:57 PM=0A= To: cerowrt-devel@lists.bufferbloat.net ; aqm@ietf.org ; bloat Subject: [aqm] ping loss "considered harmful" On this thread over here, an otherwise pretty clueful user chose=0A= openwrt's qos-scripts over the sqm-scripts, because sqm-scripts had=0A= *higher ping loss*.=0A= =0A= =0A= http://forums.dlink.com/index.php?topic=3D61634.msg251125#msg251125=0A= =0A= (I note that both fq_codel enabled QoS systems outperformed=0A= streamboost by a lot, which I am happy about)=0A= =0A= wow. It never registered to me that users might make a value judgement=0A= based on the amount of ping loss, and in looking back in time, I can=0A= think of multiple people that have said things based on their=0A= perception that losing pings was bad, and that sqm-scripts was "worse=0A= than something else because of it."=0A= =0A= sqm-scripts explicitly *deprioritizes* ping. In particular, this=0A= reduces the impact of ping floods from ipv6 to your entire /64, or to=0A= your whole ipv4, fairly well. And I had made the point that=0A= prioritizing ping was a bad idea here (including some dripping sarcasm=0A= later in the piece).=0A= =0A= http://www.bufferbloat.net/projects/cerowrt/wiki/Wondershaper_Must_Die=0A= =0A= but wow, it never occurred to me - in all these years - that ping was=0A= the next core metric on simple tests. I can be really dumb.=0A= =0A= I use netperf-wrapper and tend to ignore most of the ping data, but=0A= certainly on some benchmarks we have published ping doesn't look as=0A= good as the other stuff, *because it is deprioritized below all the=0A= other traffic*. Not strictly rate limited - as some systems do by=0A= default, including openwrt, which is impossible to get right - just=0A= deprioritized....=0A= =0A= How can we fix this user perception, short of re-prioritizing ping in=0A= sqm-scripts?=0A= =0A= -- =0A= Dave T=E4ht=0A= Let's make wifi fast, less jittery and reliable again!=0A= =0A= https://plus.google.com/u/0/107942175615993706558/posts/TVX3o84jjmb=0A= =0A= _______________________________________________=0A= aqm mailing list=0A= aqm@ietf.org=0A= https://www.ietf.org/mailman/listinfo/aqm=0A=