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 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 6179321F303 for ; Sun, 2 Mar 2014 13:48:43 -0800 (PST) Received: from hms-beagle-2.home.lan ([217.86.112.208]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0LvlWS-1XIdz20g9c-017Y6C for ; Sun, 02 Mar 2014 22:48:40 +0100 Content-Type: text/plain; charset=iso-8859-1 Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) From: Sebastian Moeller In-Reply-To: Date: Sun, 2 Mar 2014 22:48:39 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <5EC471C4-64B9-4D83-AB78-5219E2090886@gmail.com> To: Dave Taht X-Mailer: Apple Mail (2.1510) X-Provags-ID: V03:K0:tbSDm1YR0KIEfdj8geOAX31oZVJYFofU3G86AVJvbMZuvPxTYH9 bO9Tv9j7FZkZQoF7WqLcbEtuVIq0vbWAPoNZxzYR/z8DFSDPJls+FcPGfHRRXApQvnOALf6 s/ZSx+7T7d1ixeFxHk9L1sS5p+sVs66fHofUWdgmDyWslAePE/dX31PPokzrim9vcm6+ysN d6VV3zHvlMeBU+jOG7rNw== Cc: cerowrt-devel Subject: Re: [Cerowrt-devel] Better results from CeroWrt 3.10.28-16 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: Sun, 02 Mar 2014 21:48:44 -0000 Hi Dave, On Mar 2, 2014, at 22:41 , Dave Taht wrote: > Nice work! >=20 > I have a problem in that I can't remember if target autotuning made it > into that release or not. Currently there is no default auto tuning, the user needs to put = the word auto into the "target" fields in the queue discipline tab in = SQM (which is only exposed after selecting "show advanced configuration" = and "show dangerous configuration", not very user friendly, at least it = does not say 'Beware of the Leopard'...). So I am sure Rich would have = noted that. I think we need a bit of testing of the auto-tuning feature = and then make auto the default for ingest and egress. But for the = current users I did not want to change the default without some testing = (my track record of breaking things slightly comes to mind ;) ) Best Regards Sebastian >=20 > Coulde you do a tc -s qdisc show dev ge00 on your favorite of the > above and paste? I still think > target is still too low on the egress side with the current = calculation. >=20 > Secondly, now that you have a setting you like, trying pie, codel, and > ns2_codel also would be interesting. >=20 > efq_codel is currently uninteresting. Wasn't clear if you were using > nfq_codel or fq_codel throughout. >=20 >=20 > On Sun, Mar 2, 2014 at 1:18 PM, Rich Brown = wrote: >> I took some time this weekend, and ran careful speed and latency = tests on the CeroWrt 3.10.28-16 build. I have a much better = understanding of how all this works, both in theory and in practice. = Here's an executive summary of the overall test procedure with lots of = details below. >>=20 >> Adjusting CeroWrt's configured up- and download rates in the SQM page = affects both the actual data transfer rates as well as the latency. If = you set the values too low, CeroWrt will enforce that bottleneck, and = the transfer rates will be lower than you could attain on your link. If = you configure them too high, though, the transfer rates may look better, = but the latency can go off the charts. Here's how I arrived at a good = balance. >>=20 >> Test Conditions: >>=20 >> - Running tests from my MacBook Pro, 10.9.2. >> - Wi-Fi off; ethernet cable direct to Netgear WNDR3700v2 with CeroWrt = 3.10.28-16. >> - DSL service from Fairpoint, nominally "7 Mbps down/768kbps up". >> - DSL Modem sync rate (the actual rate that bits enter/leave my = house) is 7616kbps down; 864kbps up. The line is apparently fairly = clean, too. >> - Base ping time to the nearest router at ISP (via traceroute) is = 29-30 msec. >> - To minimize other traffic, I turned off most of the computers at = home, and also quit my mail client (which is surprisingly chatty). >>=20 >> The Tests: >>=20 >> I ran two different tests: netperf-wrapper with the RRUL test, and = speedtest.net. These give very different views of performance. RRUL = really stresses the line using multiple simultaneous up and download = streams. Speedtest.net is a consumer test that only tests one direction = at a time, and for a short time. We want to look good with both. >>=20 >> For the RRUL tests, I invoked netperf-wrapper like this: = netperf-wrapper rrul -p all_scaled -l 60 -H atl.richb-hanover.com -t = text-shown-in-chart >> For the Speedtest.net tests, I used their web GUI in the obvious way. >>=20 >> For both tests, I used a script (pingstats.sh, see my next message) = to collect the ping times and give min, max, average, median, and 10th = and 90th percentile readings. >>=20 >> Test Procedure: >>=20 >> I ran a series of tests starting with the up/down link rates spelled = out by Sebastian Moeller's amazingly detailed note last week. See = https://lists.bufferbloat.net/pipermail/cerowrt-devel/2014-February/002375= .html Read it carefully. There's a lot of insight available there. >>=20 >> The initial configuration was 6089/737 down/up, with the (nearly = default) values for Queue Discipline (nfq_codel, simple.qos, ECN on for = ingress; NOECN for egress, auto for both ingress and egress latency = targets), and ATM link layer with 44 bytes of overhead. >>=20 >> With those initial configuration values, latency was good but the = speeds were disappointing. I then re-ran the tests with CeroWrt = configured for higher up/down link speeds to see where things broke. >>=20 >> Things got better and better with increasing link rates until I hit = 7600/850 - at that point, latency began to get quite large. (Of course, = with SQM disabled, the latency got dreadful.) >>=20 >> There was an anomaly at 7000/800 kbps. The 90th percentile and max = numbers jumped up quite a lot, but went *down* for the next test in the = sequence when I increased the upload speed to 7000/830. I ran the = experiment twice to confirm that behavior. >>=20 >> I should also note that in the course of the experiment, I re-ran = many of these tests. Although I did not document each of the runs, the = results (speedtest.net rates and the pingstats.sh values) were quite = consistent and repeatable. >>=20 >> Conclusion: >>=20 >> I'm running with CeroWrt 3.10.28-16 configured for down/up 7000/830, = (nearly) default Queue Discipline and ATM+44 bytes of overhead. With = these configurations, latency is well in hand and my network is pretty = speedy. >>=20 >> We need to figure out how to explain to people what to expect re: the = tradeoff between "faster speeds" that show up in Speedtest.net (with = accompanying crappy performance) and slightly slower speeds with a *way* = better experience. >>=20 >> The data follows... >>=20 >> Rich >>=20 >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>=20 >> RRUL Tests: The charts associated with these RRUL runs are all = available at http://richb-hanover.com/rrul-tests-cerowrt-3-10-28-16/ >>=20 >> 6089/737: >> Min: 28.936 10pct: 29.094 Avg: 40.529 Median: 37.961 90pct: = 52.636 Max: 77.171 Num pings: 77 >>=20 >> 6200/750: >> Min: 28.715 10pct: 29.298 Avg: 41.805 Median: 39.826 90pct: = 57.414 Max: 72.363 Num pings: 77 >>=20 >> 6400/800: >> Min: 28.706 10pct: 29.119 Avg: 39.598 Median: 38.428 90pct: = 52.351 Max: 69.492 Num pings: 78 >>=20 >> 6600/830: >> Min: 28.485 10pct: 29.114 Avg: 41.708 Median: 39.753 90pct: = 57.552 Max: 87.328 Num pings: 77 >>=20 >> 7000/800: >> Min: 28.570 10pct: 29.180 Avg: 46.245 Median: 42.684 90pct: = 62.376 Max: 169.991 Num pings: 77 >> Min: 28.775 10pct: 29.226 Avg: 43.628 Median: 40.446 90pct: = 60.216 Max: 121.334 Num pings: 76 (2nd run) >>=20 >> 7000/830: >> Min: 28.942 10pct: 29.285 Avg: 44.283 Median: 45.318 90pct: = 58.002 Max: 85.035 Num pings: 78 >> Min: 28.951 10pct: 29.479 Avg: 43.182 Median: 41.000 90pct: = 57.570 Max: 74.964 Num pings: 76 (2nd run) >>=20 >> 7600/850: >> Min: 28.756 10pct: 29.078 Avg: 55.426 Median: 46.063 90pct: = 81.847 Max: 277.807 Num pings: 84 >>=20 >> SQM Disabled: >> Min: 28.665 10pct: 29.062 Avg: 1802.521 Median: 2051.276 = 90pct: 2762.941 Max: 4217.644 Num pings: 78 >>=20 >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>=20 >> Speedtest.net: First values are the reported down/up rates in the = Speedtest GUI >>=20 >> 6089/737: >> 5.00/0.58 >> Min: 28.709 10pct: 28.935 Avg: 33.416 Median: 31.619 90pct: = 38.608 Max: 49.193 Num pings: 45 >>=20 >> 6200/750: >> 5.08/0.58 >> Min: 28.759 10pct: 29.055 Avg: 33.974 Median: 32.584 90pct: = 41.938 Max: 46.605 Num pings: 44 >>=20 >> 6400/800: >> 5.24/0.60 >> Min: 28.447 10pct: 28.826 Avg: 34.675 Median: 31.155 90pct: = 41.285 Max: 81.503 Num pings: 43 >>=20 >> 6600/830: >> 5.41/0.65 >> Min: 28.868 10pct: 29.053 Avg: 35.158 Median: 32.928 90pct: = 44.099 Max: 51.571 Num pings: 44 >>=20 >> 7000/800: >> 5.73/0.62 >> Min: 28.359 10pct: 28.841 Avg: 35.205 Median: 33.620 90pct: = 43.735 Max: 54.812 Num pings: 44 >>=20 >> 7000/830: >> 5.74/0.65 (5.71/0.62 second run) >> Min: 28.605 10pct: 29.055 Avg: 34.945 Median: 31.773 90pct: = 42.645 Max: 54.077 Num pings: 44 >> Min: 28.649 10pct: 28.820 Avg: 34.866 Median: 32.398 90pct: = 43.533 Max: 69.288 Num pings: 56 (2nd run) >>=20 >> 7600/850: >> 6.20/0.67 >> Min: 28.835 10pct: 28.963 Avg: 36.253 Median: 34.912 90pct: = 44.659 Max: 54.023 Num pings: 48 >>=20 >> SQM Disabled: >> 6.46/0.73 >> Min: 28.452 10pct: 28.872 Avg: 303.754 Median: 173.498 90pct: = 499.678 Max: 1799.814 Num pings: 45 >> _______________________________________________ >> Cerowrt-devel mailing list >> Cerowrt-devel@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/cerowrt-devel >=20 >=20 >=20 > --=20 > Dave T=E4ht >=20 > Fixing bufferbloat with cerowrt: = http://www.teklibre.com/cerowrt/subscribe.html > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel