[Cerowrt-devel] qos/aqm script testers wanted

Dave Taht dave.taht at gmail.com
Sun Apr 15 00:35:02 EDT 2012

This is an example:


It would be nice to have netperf output parsed into a better format...

On Sat, Apr 14, 2012 at 9:07 PM, Dave Taht <dave.taht at gmail.com> wrote:
> I have, over the past year, looked at more streams, and qos/shaping
> models, than I care to think about.
> sfqred is the culmination of the first part of the effort and it's
> proving to be hairy.
> I finally got fed up with trying to make it all work out of lua and
> tossed off this one, which addresses the
> major parameters I've noticed as making a difference in today's environments.
> https://github.com/dtaht/deBloat/blob/master/src/simple_qos.sh
> The hairy red-related calculations (that needed lua) are currently
> elided, and this works best in the 2-4Mbit range.
> However, I could use some data from various tools, from people,
> hitting various sites in order to scale up and down better.
> Twiddle the hard coded uplink and PPOE variables in the script, then...
> IFACE=ge00 ./simple_qos.sh
> What I'm interested in:
> ADSL users operating at 1Mbit or less, as well as 10Mbit
> Verizon at 25Mbit
> Cable at 2, 4Mbit uplinks
> Other, weirder, technologies
> In the script, if you want to hammer at finding good values...
> I note that depth can be easily reduced to 20 or less in the median case.
> And the the red parameters are terribly minimal. I got some data from
> a verizon 25/25 site
> that I simply couldn't make fit any curve.
> I'm not at present doing ingress shaping, I will eventually.
> I do a variety of tests -
> 0) ALWAYS run a ping.
> During any of these tests, I ping away trying to keep ping RTT flat. I
> log these pings, too. fping is good, you can set it up to ping on 10ms
> intervals with larger than normal packets, to look more like voip.
> 1) I hit speedtest.net sites 4,30, and 90ms away in the US. Monkey
> Brains in SF has ECN enabled (as does my laptop)
> So I take their number with this script off
> tc qdisc del dev ge00 root
> Plug it into a script like this
> and try it again (while pinging! It's latency under load we need to fix)
> 2) Netperf. The version of netperf on the router supports
> classification. It's generally better to install and run netperf from
> svn on a wired or wireless laptop...
> After things work well with one stream, I fire up more and more...
> then twiddle with the TCP_RR test, TCP_MAERTS,
> ipv6, etc, etc
> a typical command line is:
> netperf -Y AF42,AF42 -l 60 -H huchra.bufferbloat.net -t TCP_STREAM &
> netperf -Y AF42,AF42 -l 60 -H huchra.bufferbloat.net -t TCP_RR &
> Which exercises the priority queue which is set to 33% of the bandwidth.
> netperf -l 60 -H huchra.bufferbloat.net -t TCP_STREAM & # sometimes 50 or more
> netperf -l 60 -H huchra.bufferbloat.net -t TCP_RR &
> Does best effort. (CEIL - a little). Note the -l 60. Frankly, 10
> minutes of data with
> a packet capture is often far more revealing than 60 seconds...
> I'll sometimes run 50 or more of these sorts of things, to observe
> when, for example
> tcp streams get starved and can't get out of slow start.
> There are netperf servers setup on machines here, with both IPv6 and
> IPv4 support, they are
> huchra.bufferbloat.net
> carme.lab.bufferbloat.net # this machine appears to have problems
> io.lab.bufferbloat.net
> I try to capture the output of
> tc -s qdisc show dev ge00  >> /tmp/log
> tc -s class show dev ge00 >> /tmp/log
> after each one.
> Anyway, happy hacking. It is my hope to automate the iterative process
> of finding the 'more right numbers'
> within reason...
> I note also the output of shaperprobe is often interesting. It's not
> installed by default can
> --
> Dave Täht
> SKYPE: davetaht
> US Tel: 1-239-829-5608
> http://www.bufferbloat.net

Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608

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