From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6C16C3CB94; Fri, 22 Jan 2016 02:05:09 -0500 (EST) Received: from hms-beagle.home.lan ([217.247.221.45]) by mail.gmx.com (mrgmx001) with ESMTPSA (Nemesis) id 0M54s2-1aCwdd3Xd0-00zJSq; Fri, 22 Jan 2016 08:05:03 +0100 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) From: moeller0 In-Reply-To: <6ACF3DA5-AEA7-43DD-A3BA-33F680374F09@gmail.com> Date: Fri, 22 Jan 2016 08:05:01 +0100 Cc: Michael Richardson , make-wifi-fast@lists.bufferbloat.net, "cerowrt-devel@lists.bufferbloat.net" Content-Transfer-Encoding: quoted-printable Message-Id: <65F6D3A9-3C63-439B-AA7D-3A667645893E@gmx.de> References: <6737994D-CE0B-46F5-B55C-A584FF6A8014@gmail.com> <23342.1453133686@dooku.sandelman.ca> <6ACF3DA5-AEA7-43DD-A3BA-33F680374F09@gmail.com> To: Jonathan Morton X-Mailer: Apple Mail (2.2104) X-Provags-ID: V03:K0:5tXRh/v7GRjjEzXqCy77Md+BqBsouYTDBPcaMVUDQQinQEeGPYl AtxuByGzOn4JTnR5kN4jllF8Z2NHKVe6nn1wEF4NTLzNEZcQRXJW3kTigcy9K0hHr+58k6E 6+4IinzjJRepJ96gJD6M0oz17FtaGmL548M3jUM87ng0x0Ny2sgzshWEw2zgDjGQ+EgJasn uyo0fawC0qr9gqE+3izNA== X-UI-Out-Filterresults: notjunk:1;V01:K0:vjdvT+mnqCI=:n8xbRf5ox8gYXRkwZs1m6G +laHNdi0wfOvx1tRnauzwDw67msgqZTt3d2tIE8kpLAIzFCpbC7bzL+fMNsTvZTdW/V9icI2O 7i2TdWwm/4dFafg4630c0FdNBVp7o/JNQhCSaoZGKQf7vG+G059yAMrEjOH3vmzeroXRkn4Ka I8TGJYDHL3+Hp8wQB/RsllCYguP3+BeFmD11eh2iO4KfBG96D8FQWaZRL1DCULnCA2IWfWGV3 mRaq5M0yMqP/FvwK4SgzTDmw/aER7RlKuDCOmP82B1dH8ZmrL6oY8bqm++I7+Yl5F1+OlQEx8 Re5eSfDXOz98vmuOpgWS/kw2QRMjAdVDb6s7ALZ3U92s53niG9GW0ruh/rNrZuyi/hLrGmg3V 9rWRK3Xdwe8uRZtB8Wc7i5jG4LoPTvb43bI777RUpztoirsjTceplZxeQMlF6dCZMovcRPC/f sITtCC8GFOg7dieE/nslnEgDlAsZpljbmLDU6PP7ZpxFZLO2e6ppb4AL9E074NTZt/dg5cDa3 BpMUKROfan0hSGONbrL5AV8QlBR6U0DfITrODFQPognPyz0G9JImt/o9H5MzZO4OHFRa4b+Kf Uytkaeti6syMo1qN1032g1D7kWKspRQJ0YuU/+NZM0KRc5iiEz/xedhCXBcvBnxwTQZMb3pBQ MihLPsz66dsMvbZNguGAZljXuMgOooytOavgaEIjKmClTZMKS9dGWTtXQfUEQr93UgEgPOetY x5irvmxAecCUjpXkpN4ATAbNjYl88TcFK0UnoEuH9fLHHKZ74sru37cJGP8/wtGGWlxHA1x1z Xoc9FVN Subject: Re: [Cerowrt-devel] routers you can throw off the back of a truck X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 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: Fri, 22 Jan 2016 07:05:09 -0000 Hi Jonathan, > On Jan 19, 2016, at 00:06 , Jonathan Morton = wrote: >=20 >>=20 >> On 18 Jan, 2016, at 18:14, Michael Richardson = wrote: >>=20 >> Jonathan Morton wrote: >>> I haven=E2=80=99t yet found a robust way to automatically sense link = capacity from >>> the upstream side. You=E2=80=99ll therefore need to set a = conservative static >>> value for the uplink capacity. >>=20 >> As the maintainer of a PPPoE concentrator, and operator of some = networks, >> I've been considering whether one can estimate the bandwidth using = round >> trip PPP IPCP keep alives. Clearly, if both ends participate in = time >> stamping then it is much better, but I've been wondering if we can do = some >> incremental deployment on one side or the other. >>=20 >> Sadly, I mostly just think about this while cycling; I haven't = written any >> code yet. >=20 > In most PPPoE deployments I know about, there is also a modem from = which the actual, precise link rates can usually be queried. Where = that=E2=80=99s not the case, IPCP (or is it LPCP?) probes would be a = reasonable workaround, but it must still be understood that the signal = it provides is only valid under saturating traffic, which complicates = implementation. Erm, if one send probes of differing sizes, one can calculate = the total effective bandwidth even without saturating the link (which = unfortunately is an inseparable compound of ingress and egress, but will = be heavily dominated by the lower, so typically the egress. And it = should be relatively simple to flood the link while sending probes, in = other words Valent=E2=80=99s router should be able to create the = saturatng load on demand ;) Best Regards Sebastian >=20 > - Jonathan Morton >=20 > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel