From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x241.google.com (mail-lf0-x241.google.com [IPv6:2a00:1450:4010:c07::241]) (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 4BF1A3B2A2 for ; Fri, 2 Dec 2016 15:32:19 -0500 (EST) Received: by mail-lf0-x241.google.com with SMTP id o20so23126944lfg.3 for ; Fri, 02 Dec 2016 12:32:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=ecjTSoS30C0S3E9bUP0JDhhCbogg+OoAb72MuONZzkQ=; b=Qr0ttsE8aOuh7ZPbJo3Byn3K1yG7MHaJ918pDd2JZHPhbL7WLaNdmVAqqoN6FTnMec 7h5xYpzgrNt91MD8SZQqA0ykUGZ5ipb6AET4OkYmFJV5neXo2Ujs95faqS6lhog9WZDp CZDqRbg7FJcg5f8LBNOipXdW0vrHObKiEsRye+Ils4KdrzjOETrK8SZc8WWaHPP/n18D yfiHYIpLSjncmRV5DbAXfQYv3SD5+jiuArHSNsJwZEX9RiSvIv+dCHTL0pykPL+0/4Id RG3/48HUYGF2FzoEZsTFxReCCLRwrMdssoJZyXTrYBSQj5sPrSqKi+IISa3AZt8OklFm K5zA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=ecjTSoS30C0S3E9bUP0JDhhCbogg+OoAb72MuONZzkQ=; b=YW6qmYSTT/yJqmQ2pkcQBaBw4EXd13db2f3SHPWumq9FhB1H/DhSRd6N3Opf0TrwOl TZEN/nLu2osrhPvRV9lMq9yw9yf1hAWiJVq6jArFXwflij+lLgpcNSXJSEfq1oN7uj3I laefNbcZSTg1EP/o2FUWfBqzRPqimDOUoAfa7pY5geNZobDrONZloyD+j7q/mLOdtyXv +olo0SLcHDp3jfBXoBSmGH5udME1EU6Zm7S+AyOAfBz0bssNhFVh3/l7rEGS3mmovVjw JjQT/Dfr3KgoDVcONkUOT25ndkjGOaELffChJ2RW4O/BXCx4WOsZtQAsUNhnf++XITGm EbNg== X-Gm-Message-State: AKaTC021Ndap74HSMGIhfjCVkL4ZaDdjmTw7eQcTQ8LEyPOkwIoTsxoaSnYDNbPelaktYw== X-Received: by 10.46.5.215 with SMTP id 206mr23396876ljf.17.1480710737944; Fri, 02 Dec 2016 12:32:17 -0800 (PST) Received: from [192.168.100.13] (37-33-82-144.bb.dnainternet.fi. [37.33.82.144]) by smtp.gmail.com with ESMTPSA id h3sm1041775lfj.27.2016.12.02.12.32.16 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 02 Dec 2016 12:32:17 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: Date: Fri, 2 Dec 2016 22:32:14 +0200 Cc: Dave Taht , "aqm@ietf.org" , bloat Content-Transfer-Encoding: quoted-printable Message-Id: <56F6A3AB-3A47-4178-BEFF-04E3DC23B039@gmail.com> References: To: Aaron Wood X-Mailer: Apple Mail (2.3124) Subject: Re: [Bloat] TCP BBR paper is now generally available 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, 02 Dec 2016 20:32:19 -0000 > On 2 Dec, 2016, at 21:15, Aaron Wood wrote: >=20 > So, how is this likely to be playing with our qos_scripts and with = cake? Cake=E2=80=99s deficit-mode shaper behaves fairly closely like an ideal = constant-throughput link, which is what BBR is supposedly designed for. = I haven=E2=80=99t read that far in the paper yet, but it shouldn=E2=80=99t= trigger any =E2=80=9Cbucket detection=E2=80=9D algorithms, because it = doesn=E2=80=99t have a =E2=80=9Cbucket=E2=80=9D. It is capable of = bursting, but only to the minimum extent required to reconcile required = throughput with timer resolution and scheduling latency; I=E2=80=99ve = tested it with millisecond timers. The older schemes involving HTB and HFSC *do* have token-bucket = behaviour, with an explicitly configured burst size (this excess traffic = will collect in downstream buffers). However, these are shapers, not = policers, so they will start delaying packets (leaving them in child = qdiscs) when the bucket is empty, not simply dropping them. The interaction with AQM-related marking and dropping will be = interesting to read, though. It=E2=80=99s not a-priori obvious how much = a shaper-AQM combination looks like a policer. - Jonathan Morton