From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 3598121F1FC for ; Sun, 8 Dec 2013 11:02:30 -0800 (PST) Received: from hms-beagle-3.home.lan ([87.150.22.181]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0LaGfK-1V9IPC0Atq-00m16N for ; Sun, 08 Dec 2013 20:02:28 +0100 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) From: Sebastian Moeller In-Reply-To: <87vbyzb5fl.wl%jch@pps.univ-paris-diderot.fr> Date: Sun, 8 Dec 2013 20:02:26 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <15B33C3B-4F1D-4CC6-AC24-CA8926047D38@gmx.de> References: <20131203222559.GV8066@einstein.kenyonralph.com> <7ieh5pew2d.wl%jch@pps.univ-paris-diderot.fr> <87haakx1ev.wl%jch@pps.univ-paris-diderot.fr> <09D8F3A0-7172-4677-9887-119813E28740@gmx.de> <877gbfcw4t.wl%jch@pps.univ-paris-diderot.fr> <87vbyzb5fl.wl%jch@pps.univ-paris-diderot.fr> To: Juliusz Chroboczek X-Mailer: Apple Mail (2.1510) X-Provags-ID: V03:K0:7CmdlPoq1cBtocIDOafwMNuWk4swUp1/SyfGRHKfLZ4Se/XiXyf bW2GQh8CKOiI+xGwzN71ZIIorU/5FvDMspcDeqtzKCfZQHen4268CCH8oZnL5Ah0Pfx/kKo xjyZ0NBogakru1l5KjV/RkS7E6n4/jrRkQQeD5MhCdEqGz+fzlvTLJgMg0unD27t5o/uCKb GKCiBXzTwrRzqOmAoMfww== Cc: bloat Subject: Re: [Bloat] curious..... X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Dec 2013 19:02:30 -0000 Hi Juliusz, On Dec 8, 2013, at 18:47 , Juliusz Chroboczek = wrote: >>> as long as you have fewer than 250 congestion-limited flows at >>> a given time. >=20 >> Currently not doing much of anything my router has 142 active >> connections (according to conntrack) >=20 > 142 active conntrack entries, as opposed to congestion-limited flows. > Roughly speaking, an active conntrack entry is a flow that has sent at > least a packet within the last minute or so, while a = congestion-limited > flow is one that sends data as fast as it reasonably can. I certainly > hope you don't have 142 congestion-limited flows on an idle router. Well, I guess the crux of the problem is that even at 100Mbit/s = with 250 packets (according to your estimate) we are not in the clear as = we can only round robin 250 equally weighted queues, and much less at = say 10Mbit/s uplinks. So opening around 90 tabs in a browser increased = the number of connections to ~2000, all of them new, so all of them will = be expedited by fq_codel. So I am still not convinced that real time = critical applications will work well if the bottleneck does not do = priority management even at 100Mbit/s. >=20 >> I still think that for VoIP prioritizing might still be required >> until supplied minimum bandwidth gets higher. >=20 > I agree, in the short term. In the medium term, I'm optimistic we can > get rid of these nasty hacks, which is why I'd rather see Dave spend > his copious free time on something else. I fully agree about Dave's time :). About prioritizing, I am less optimistic as I can not see how the system = can behave well under extreme load; I for one would be quite unhappy if = an device on my internal network could effectively DOS my ability to = make phone calls (I switched to IP telephony so this theoretical issue = has become practical for me). Or put it that way, I hope that the core internet is = over-provided and will not cause congestion, at the same time I want to = be able to max out my internet connection and still be able to phone. >=20 >> Even at 1000 symmetric I still think it would be a good idea to >> isolate really latency critical traffic from the rest, >=20 > It would certainly be good to have hard data rather than confronting > your intuitions with my back-of-the-envelope computations. (Hint, = hint.) I guess I will chime in again once I have symmetric 1000Mbit/s = link then :) I guess until I have an internet connection I cannot easily = saturate I will stubbornly stick to my conviction that some sort of hard = polity system is needed, until convinced by data :) best regards Sebastian >=20 > -- Juliusz