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 4716B21F13F for ; Mon, 6 Jan 2014 06:28:06 -0800 (PST) Received: from hms-beagle-3.home.lan ([217.254.130.56]) by mail.gmx.com (mrgmx002) with ESMTPSA (Nemesis) id 0Mfn88-1Vo7vF36Dk-00NBMm for ; Mon, 06 Jan 2014 15:27:57 +0100 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) From: Sebastian Moeller In-Reply-To: <52CABC11.6040000@imap.cc> Date: Mon, 6 Jan 2014 15:27:56 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <01558084-B7D8-448A-A4ED-CE36D18AAA97@gmail.com> <52C855B1.1040209@imap.cc> <52CA7CC3.2030203@imap.cc> <52CABC11.6040000@imap.cc> To: Fred Stratton X-Mailer: Apple Mail (2.1510) X-Provags-ID: V03:K0:pcEPa1hyWzz8WkDO7DGjKNOhRtv9NHIcfxNvqwNxp1uHLdJNA8F Ox01A2gLa7WEdd/jsMnFTfls4iMfVwYTbG3HossL2q0Y0316svYa+FeK07h04RupFnqPxs4 EjW5LKlFSJFTJDLW1DkCCEbkOajG+IBTYd1xCotMVE/z8xLskcKn31QSgi7bnnjXoL4wOtu 95nYHJ6tn26dr8meIX+vA== Cc: cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] SQM Question #5: Link Layer Adaptation Overheads X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 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: Mon, 06 Jan 2014 14:28:11 -0000 Hi Fred, On Jan 6, 2014, at 15:22 , Fred Stratton wrote: > The line rate is 11744/1022 kb/s, but changes moment to moment. SNR is = 12.1 decibel. I am using 11000/950 kb/s as settings. So 100 * 11000 / 11744 =3D 93.66% of downlink line rate and 100* = 950 / 1022 =3D 92.95 % of uplink line rate; quite impressive given the = common wisdom of 85% :). > I shall try your suggestion when there is something worth watching = live, to provide a valid comparison, which may not be before 21:30 CET = on Sunday. Oh, take your time, this is really not essential, butit would be = a nice data point for figuring out how important the correct overhead = estimate really is in real life, theory being theory and all=85 Best Regards Sebastian >=20 > On 06/01/14 14:12, Sebastian Moeller wrote: >> Hi Fred, >>=20 >>=20 >> On Jan 6, 2014, at 10:52 , Fred Stratton = wrote: >>=20 >>> I have been operating the latest build with 6relayd disabled. The = henet /48 I have been allocated is subnetted correctly, presumably by = dnsmasq. >>>=20 >>> I adopted the suggestions to use nfq_codel and an egress target of = 25ms , with an overhead of 40 on a PPPoE connection. I chose to watch = the first 2 episodes of the 3 part third series of 'Sherlock', live on = iPlayer, and these streamed correctly and uninterrupted for 90 minutes. = This was not previously possible. (Quite whether they were up to the = standard of previous episodes is another matter.) >>>=20 >>> I can watch iPlayer with little stutter whilst downloading Arch = Linux by torrent, downloading other files at the same time. >>>=20 >>> So, for a relatively slow ADSL2+ line, the current build works well. >> Out of curiosity, to what percentage of the "current line rate" = (you know the one reported by your modem) you shaped up- and downlink? = And in case you have too much time on your hand, how does the same feel = with an overhead of 10 (to see how bad an overhead underestimate would = feel for a user), since you currently happen to have a quite sensitive = subjective latency evaluation system set up :)=85 >>=20 >> Best Regards >> Sebastian >>=20 >>>=20 >>> On 06/01/14 03:29, Dave Taht wrote: >>>> On Sat, Jan 4, 2014 at 10:40 AM, Fred Stratton = wrote: >>>>> Link Names: >>>>>=20 >>>>> For consistency, if ADSL is used as a portmanteau term, them VDSL = should be >>>>> used as the equivalent for VDSL and VDSL2. >>>>>=20 >>>>> CeroWRT has to decide whether it is an experimental build, or = something that >>>>> will eventually be used in production, so these decisions can be = made >>>>> consistently. >>>> Well, what I was aiming for was for us to get the sqm scripts and = gui >>>> up to where they were better than the standard openwrt qos scripts = and >>>> then push them up to openwrt to where they could be more widely >>>> deployed. >>>>=20 >>>> Aside from being able to dynamically assign priorities in the gui, = we >>>> are there. Except that nfq_codel is currently getting better = results >>>> than fq_codel at low bandwidths, and I'm tempted to pour all of >>>> simple.qos into C. >>>>=20 >>>> As for cero's future - certainly since all the snowden revelations >>>> I've been going around saying that "friends don't let friends run >>>> factory firmware". I would like a stable build of sqm and cerowrt = to >>>> emerge, and to then go off and work on improving wifi. Regrettably >>>> what seems to be happening is more backwards than forwards on the >>>> former, and ramping up on the ath9k and ath10k is taking more time >>>> than I'd like, and it seems likely I'll be working on those = primarily >>>> on another platform and only eventually pushing the results out to >>>> cero, mainline kernel >>>>=20 >>>> So it's still at the "keep plugging away" point for sqm, ipv6, cero = in >>>> general, with the stable release always just out of sight. >>>>=20 >>>> Tackling the ipv6 problem is next on my agenda on cero, and getting = a >>>> test suite going is next on my day job. >>>>=20 >>>>> I concur with your ADSL setup suggestion as default. I have been = running the >>>>> Sebastian Moeller ping script overnight to calculate ADSL overhead = for the >>>>> last several days. After several hours of curve fitting using = Octave, an >>>>> overhead result is displayed. This novel approach works well. >>>> It would be nice to get to where we could autoconfigure a router = using >>>> tools like these with no human intervention. This includes = bandwidth >>>> estimation. >>>>=20 >>>>> The overhead for the particular setup I use was 40 for PPPoE, and = 10 for >>>>> PPPoA. >>>>>=20 >>>>> The default you suggest is a suitable starting point, I suggest. >>>>>=20 >>>>>=20 >>>>> On 04/01/14 18:16, Rich Brown wrote: >>>>>> QUESTION #5: I still don=92t have any great answers for the Link = Layer >>>>>> Adaptation overhead descriptions and recommendations. In an = earlier message, >>>>>> (see >>>>>> = https://lists.bufferbloat.net/pipermail/cerowrt-devel/2013-December/001914= .html >>>>>> and following messages), Fred Stratton described the overheads = carried by >>>>>> various options, and Sebastian Moeller also gave some useful = advice. >>>>>>=20 >>>>>> After looking at the options, I despair of giving people a clear >>>>>> recommendation that would be optimal for their equipment. = Consequently, I >>>>>> believe the best we can do is come up with =93good enough=94 = recommendations >>>>>> that are not wrong, and still give decent performance. >>>>>>=20 >>>>>> In this spirit, I have changed Draft #3 of the =93Setting up SQM=94= page to >>>>>> reflect this understanding. See >>>>>> = http://www.bufferbloat.net/projects/cerowrt/wiki/Setting_up_AQM_for_CeroWr= t_310 >>>>>>=20 >>>>>> ADSL/ATM link: Choose =93ADSL/ATM", and set Per Packet = Overhead to >>>>>> 40 >>>>>> VDSL2 link: Choose =93VDSL=94, and set Per Packet = Overhead to 8 >>>>>> Other kind of link (e.g., Cable, Fiber, Ethernet, other = not >>>>>> listed): Choose =93None (default)=94, and set Per Packet Overhead = to 0 >>>>>>=20 >>>>>> NB: I have changed the first menu choice to =93ADSL/ATM=94 and = the second to >>>>>> =93VDSL=94 in the description. I would ask that we change to GUI = to reflect >>>>>> those names as well. This makes it far easier/less confusing to = talk about >>>>>> the options. >>>>>>=20 >>>>>> As always, I welcome help in setting out clear recommendations = that work >>>>>> well for the vast majority of people who try CeroWrt. Thanks. >>>>>>=20 >>>>>> Rich >>>>>> _______________________________________________ >>>>>> Cerowrt-devel mailing list >>>>>> Cerowrt-devel@lists.bufferbloat.net >>>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel >>>>> _______________________________________________ >>>>> Cerowrt-devel mailing list >>>>> Cerowrt-devel@lists.bufferbloat.net >>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel >>>>=20 >>> _______________________________________________ >>> Cerowrt-devel mailing list >>> Cerowrt-devel@lists.bufferbloat.net >>> https://lists.bufferbloat.net/listinfo/cerowrt-devel >=20