From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from eu1sys200aog117.obsmtp.com (eu1sys200aog117.obsmtp.com [207.126.144.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 1236921F100 for ; Sun, 8 Dec 2013 08:01:30 -0800 (PST) Received: from mail.la.pnsol.com ([89.145.213.110]) (using TLSv1) by eu1sys200aob117.postini.com ([207.126.147.11]) with SMTP ID DSNKUqSX039E/FaJbis/RTubw55459qyipL8@postini.com; Sun, 08 Dec 2013 16:01:31 UTC Received: from ba6-office.pnsol.com ([172.20.5.199]) by mail.la.pnsol.com with esmtp (Exim 4.76) (envelope-from ) id 1VpgnL-0007Uk-GW; Sun, 08 Dec 2013 16:01:23 +0000 Content-Type: multipart/alternative; boundary="Apple-Mail=_E12805DC-7CED-429E-807D-F06EF6661952" Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) From: Neil Davies In-Reply-To: <09D8F3A0-7172-4677-9887-119813E28740@gmx.de> Date: Sun, 8 Dec 2013 16:01:23 +0000 Message-Id: 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> To: Sebastian Moeller X-Mailer: Apple Mail (2.1510) Cc: bloat , Juliusz Chroboczek 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 16:01:31 -0000 --Apple-Mail=_E12805DC-7CED-429E-807D-F06EF6661952 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 On 8 Dec 2013, at 10:40, Sebastian Moeller wrote: > ... > Is that really true? given enough concurrent flows, critical = flows might be delayed purely be the round robin scheduling of equally = "worthy" packets in fq_codel, so some residual priory system might still = make sense=85 =10 Sebastian - you are describing a property that we've measured in large = scale (countrywide) deployed networks, it is also the underlying = property that is causing mobile network operators issues with packet = based networks as backhaul, as well as several other mission critical = environments we've had dealings with. When I pointed out that such service approaches will create extreme = non-stationarity (in the particular case 2+ seconds) - the designers = said - not their problem, not in their brief from management, they were = told to bandwidth share. It is not just that the 2+ seconds can exist, but that the overall = system (under the right offered traffic pattern) WILL display that = dynamic property. Neil --Apple-Mail=_E12805DC-7CED-429E-807D-F06EF6661952 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 moeller0@gmx.de> = wrote:
...
Is that really true? given enough = concurrent flows, critical flows might be delayed purely be the round = robin scheduling of equally "worthy" packets in fq_codel, so some = residual priory system might still make = sense=85
=10

Sebastian - you are = describing a property that we've measured in large scale (countrywide) = deployed networks, it is also the underlying property that is causing = mobile network operators issues with packet based networks as backhaul, = as well as several other mission critical environments we've had = dealings with.

When I pointed out that such = service approaches will create extreme non-stationarity (in the = particular case 2+ seconds) - the designers said - not their problem, = not in their brief from management, they were told to bandwidth = share.

It is not just that the 2+ seconds can = exist, but that the overall system (under the right offered traffic = pattern) WILL display that dynamic = property.

Neil

= --Apple-Mail=_E12805DC-7CED-429E-807D-F06EF6661952--