From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) (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 C5CE23B29E for ; Mon, 24 Apr 2017 03:56:03 -0400 (EDT) Received: from [172.17.3.97] ([134.76.241.253]) by mail.gmx.com (mrgmx103 [212.227.17.168]) with ESMTPSA (Nemesis) id 0M7ojs-1c7JSy26eO-00vQ9n; Mon, 24 Apr 2017 09:55:52 +0200 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) From: Sebastian Moeller In-Reply-To: Date: Mon, 24 Apr 2017 09:55:50 +0200 Cc: Dendari Marini , cake@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <2FFBF256-2932-4FC7-AD1F-0D7CEE111809@gmx.de> References: <05C0B0C7-4337-4115-AC6B-DA81392FCB34@gmail.com> <22E633CF-5EE0-4B0F-89A8-B790E730FB6C@gmx.de> <0BA3EE91-C5BC-4155-9D5D-D15D34490A1A@gmx.de> <00DDAA0B-7D99-489B-BA2D-1F20289409B3@gmx.de> To: David Lang X-Mailer: Apple Mail (2.3273) X-Provags-ID: V03:K0:NlShJZaz7RKmnkd/qeyKIMqIfLuiCtCBgxij6T18ZpHNnog9lf/ WpBAch82oY9DX11Sdeu+MVFd3ETRdB+mpyiQ5c5nUXnFeMRhqCuzl9cAflZKMnLdwIcDS+z bTqU0pWoOKx69+ccdLu+EaKYxbugdb2UJsSIcFEdX2pUDWRJDhFYecK8+ICys3U1BaYH0da FEWFQ88yf98aKoAD06jfw== X-UI-Out-Filterresults: notjunk:1;V01:K0:xmycjmPPQbM=:uxm669APa0o+MtBGVltvsU DwApF0w2FPsKQQMOtsiBd0M61ivQk+qSH3KnnjSVKeyGg3D6oBIEPG+c4U/i66cqQCeIiI+Ws qRiJRjj8eH+BuZUW7eKIRsIkRjtgoKC4UbQPMk933S9nftRBayrSza+5nTI7oahisnV5YW3Pe R7B0FdZWAyvbC6rgoK104sE+44odhjKCyRFQ+osvZ2t3MwtLRa6VsZTrtv7mYzky5IHDlXSm/ r+zwt7lyDqkzy1YJHYDEGme7Yde3rF+Skw/CfmxiTdD7LPDVVh48DEibmHzuUXbIRyFImIVfu T+w+Wk6ulq2+7Z6qU2QlOgcNZXkxatTSmqgk+sSFLGcqwFoJ7a1H3i0x16C5Ko2WazaRBznly 3PH29MS5HytVl1h/V/bEWy6YhjTFA0k/NYkibbkbGiwm1glqu25oBh2XpQ2JuPtUIwj/hudw1 o956Lh+HmJC/mV8JtKqpLktAkgjOYEoGWhM6CFS95zpvA4VLxuajcckvVXdE2Y8U9XW9anO72 gMt7YvnvjP0Q1U0iMiVtox1jSBaQNQBERfZ0nqn/qvP3/Wcr21jP0tGuO9zaUnDVEPzCIu5ZP dcKJ00kVCRt7tg4XaOFmBiB6wNmLz6bQC07kvE4Y3CM+wVt6wU2rjgo/fzlwl5qbTLRAn7evH w9QqRFe0J4exkn8KuWXioKv/WD19bBjyxgidA3le1yDWIXgG23A+z+P16rdIKp26NovhMvLZF Pe67egXqIcYGK1sKTWNP+bvCvkuQQim618YCIAUr74slHI0ba4jxGZgdlAqulQivNUzf2/HBl uZaXcZ3 Subject: Re: [Cake] Getting Cake to work better with Steam and similar applications X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Apr 2017 07:56:04 -0000 Hi David, > On Apr 23, 2017, at 14:32, David Lang wrote: >=20 > On Sun, 23 Apr 2017, Sebastian Moeller wrote: >=20 >>> About the per-host fairness download issue: while it's kinda = resolved I still feel like it's mainly related to Steam, as normally = downloading files from PC1 and PC2 halved the speed as expected even at = full bandwidth (so no overhead, no -15%). >>=20 >> This might be true, but for cake to meaningfully resolve = bufferbloat you absolutely _must_ take care to account for encapsulation = and overhead one way or another. >=20 > well, one way to account for this overhead is to set the allowed = bandwidth low enough. Being precise on this overhead lets you get closer = to the actual line rate, but if you have enough bandwidth, it may not = really matter (i.e. if you have a 100Mb connection and only get 70Mb out = of it, you probably won't notice unless you go looking) Violent agreement. But note that with AAL5=E2=80=99s rule to = always use an integer number of ATM cells per user packet the required = bandwidth sacrifice to statically cover the worst case gets ludicrous = (theoretical worst case: requiring 2 53 byte ATM cells for on 49 Byte = data packet: 100 * 49 / (53 * 2) =3D 46.2% and this is on top of any = potential unaccounted overhead inside the 49 Byte packet). Luckily the = ATM padding issue is not as severe for bigger packets=E2=80=A6 but still = to statically fully solve modem/dslam bufferbloat the required bandwidth = sacrifice seems excessive=E2=80=A6 But again you are right, there might = be users who do not mind to go to this length. For this reason I = occasionally recommend to start the bandwidth at 50% to certainly rule = out overhead/encapsulation accounting issues (mind you take 50% as = starting point from which to ramp up=E2=80=A6) Best Regards Sebastian. >=20 > David Lang