From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) (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 CF6C23BA8E; Fri, 15 Mar 2019 15:32:09 -0400 (EDT) Received: by mail-lj1-x233.google.com with SMTP id v10so8939555lji.3; Fri, 15 Mar 2019 12:32:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=OahIFpBBo1B77IoSx/03LOaMZlJR99kXRJk9iN+fqNQ=; b=MIlEYHQeH8GLJkg/gQsEUncaVglaafzB8POQFOxi9CRs22PposkI8VeBua8VvjKY4s mnJ4j0Odn52hXG8L/kXDalGM/vTHMMjtRqCC21eaiGRykHAthaJxZktShfI+Gl2NSX/Z heuRFm7MYups879hovcmGD54dDcfplnDwO7vs4khXYh/1saD4AMVdKX4EfUV0Lc+NbtJ lmEfjDneEH1LfjeqwIQjrnOZ3NK9PcVP9zjtGv9meSoR9NhszmCPiBAIcdcpTJgOGekT A6QrsAZDMdUSw/XdG1nIdJFiI7tLmi1thvSSEfcao+vkVIOvJlZdVrurhejq6R5SRrOB tA7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=OahIFpBBo1B77IoSx/03LOaMZlJR99kXRJk9iN+fqNQ=; b=YGtvyg97/qNpt3mYsuw4q+BJQArv76eli6g+nttTs1XrJeXOiRuPhYkrhjSYyoaZSe KHTThNHGtMhhJ9Qa2fIwzZhjTV+/iPNB72DMkpTHACLfS3wye0MPqr02Wq/NJ5LhW/Kv i5hwxuZHw4Cv7LhO4E+Y6NDray8LAzJtyzWNkbc7jKhXGAYov59iK3CRr48YEILJLPav BfoHipmYqhawmPtdZc7W/8p0kdurBjLFCU0GWJtrGEU9fBvwfBAH830TCRp/25rzzrA2 GYeXePkbFcw4RSamkCzmthag0ppA9gNbNlkKVu9yjoLW8iqVxpq3Xlxo2M4j5Photz3m uoGw== X-Gm-Message-State: APjAAAWCsd5hdjKZC+BBoaorUvGzLezcWPWXSCuMWaL5s7ZfxHmzXQ+K be63agZBe5DHUQvhdyaq3Js= X-Google-Smtp-Source: APXvYqw2em4Afy2kwJcQG1bu0mPSkriZIAtjR7rQFFn0SZWs7nYi1hOFoGufbkjTYeSyuy5NXZij1g== X-Received: by 2002:a2e:9a49:: with SMTP id k9mr614209ljj.84.1552678328662; Fri, 15 Mar 2019 12:32:08 -0700 (PDT) Received: from jonathartonsmbp.lan (83-245-235-46-nat-p.elisa-mobile.fi. [83.245.235.46]) by smtp.gmail.com with ESMTPSA id r80sm594240lja.28.2019.03.15.12.32.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Mar 2019 12:32:08 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Jonathan Morton In-Reply-To: Date: Fri, 15 Mar 2019 21:32:06 +0200 Cc: "David P. Reed" , ecn-sane@lists.bufferbloat.net, bloat Content-Transfer-Encoding: quoted-printable Message-Id: <7412ADED-D1F3-4C15-9703-0977E087013B@gmail.com> References: <1E80578D-A589-4CA0-9015-B03B63042355@gmx.de> <27FA673A-2C4C-4652-943F-33FAA1CF1E83@gmx.de> <1552669283.555112988@apps.rackspace.com> To: Mikael Abrahamsson X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Bloat] [Ecn-sane] [iccrg] Fwd: [tcpPrague] Implementation and experimentation of TCP Prague/L4S hackaton at IETF104 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: Fri, 15 Mar 2019 19:32:10 -0000 > On 15 Mar, 2019, at 8:36 pm, Mikael Abrahamsson = wrote: >=20 > Having a "lower-than-best-effort" diffserve codepoint might work, = because it means worse treatment, not preferential treatment. >=20 > The problem with having DSCP CPs that indicate preferential treatment = is typically a ddos magnet. This is true, and also why I feel that just 2 bits should be sufficient = for Diffserv (rather than 6). They are sufficient to express four = different optimisation targets: 0: Maximum Throughput (aka Best Effort) 1: Minimum Cost (aka Least Effort) 2: Minimum Latency (aka Maximum Responsiveness) 3: Minimum Loss (aka Maximum Reliability) It is legitimate for traffic to request any of these four optimisations, = with the explicit tradeoff of *not* necessarily getting optimisation in = the other three dimensions. The old TOS spec erred in specifying 4 non-exclusive bits to express = this, in addition to 3 bits for a telegram-office style "priority level" = (which was very much ripe for abuse if not strictly = admission-controlled). TOS was rightly considered a mess, but was = replaced with Diffserv which was far too loose a spec to be useful in = practice. But that's a separate topic from ECN per se. - Jonathan Morton