Nice work! I have a problem in that I can't remember if target autotuning made it into that release or not.
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. Secondly, now that you have a setting you like, trying pie, codel, and ns2_codel also would be interesting. efq_codel is currently uninteresting. Wasn't clear if you were using nfq_codel or fq_codel throughout. On Sun, Mar 2, 2014 at 1:18 PM, Rich Brown <[email protected]> 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. > > 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. > > Test Conditions: > > - 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). > > The Tests: > > 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. > > 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. > > 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. > > Test Procedure: > > 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. > > 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. > > 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. > > 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.) > > 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. > > 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. > > Conclusion: > > 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. > > 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. > > The data follows... > > Rich > > ================================================================ > > RRUL Tests: The charts associated with these RRUL runs are all available at > http://richb-hanover.com/rrul-tests-cerowrt-3-10-28-16/ > > 6089/737: > Min: 28.936 10pct: 29.094 Avg: 40.529 Median: 37.961 90pct: 52.636 > Max: 77.171 Num pings: 77 > > 6200/750: > Min: 28.715 10pct: 29.298 Avg: 41.805 Median: 39.826 90pct: 57.414 > Max: 72.363 Num pings: 77 > > 6400/800: > Min: 28.706 10pct: 29.119 Avg: 39.598 Median: 38.428 90pct: 52.351 > Max: 69.492 Num pings: 78 > > 6600/830: > Min: 28.485 10pct: 29.114 Avg: 41.708 Median: 39.753 90pct: 57.552 > Max: 87.328 Num pings: 77 > > 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) > > 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) > > 7600/850: > Min: 28.756 10pct: 29.078 Avg: 55.426 Median: 46.063 90pct: 81.847 > Max: 277.807 Num pings: 84 > > SQM Disabled: > Min: 28.665 10pct: 29.062 Avg: 1802.521 Median: 2051.276 90pct: > 2762.941 Max: 4217.644 Num pings: 78 > > ================================================================ > > Speedtest.net: First values are the reported down/up rates in the Speedtest > GUI > > 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 > > 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 > > 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 > > 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 > > 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 > > 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) > > 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 > > 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 > [email protected] > https://lists.bufferbloat.net/listinfo/cerowrt-devel -- Dave Täht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel
