[Cerowrt-devel] performance numbers from WRT1200AC (Re: Latest build test - new sqm-scripts seem to work; "cake overhead 40" didn't)

Dave Taht dave.taht at gmail.com
Sat Jun 27 13:59:16 EDT 2015

On Fri, Jun 26, 2015 at 10:50 PM, Mikael Abrahamsson <swmike at swm.pp.se> wrote:
> On Fri, 26 Jun 2015, Dave Taht wrote:
>> your results are showing basically tail drop behavior. Although I
>> would have expected intrinsic delay on the link to crack 100mbits on
>> the rrul test, not 20ms (which is still high), and you only hit 7 on
>> the single threaded tcp up test, based on what I saw in the driver.
>> turn off sqm, stay at 100mbit, let fq_codel ride, try the rrul_50_up
>> test. Also do a capture to see if CE was ever exerted.
> http://swm.pp.se/aqm/rrul_50_up-2015-06-27T072819.166452.iperf3_150626_9_100M.flent.gz
> I have a capture of this as well, it's 1.5gigs. It has lots of mentions of
> ECT(0) but 0 mention of ECT(1). TOS should be 0x3 when the EC=1 ? I see no
> such packets. All the packets are 0x2.
> http://swm.pp.se/aqm/rrul_50up-100M.pcap.bz2

Maybe you are dropping at the internal switch? A lot of manufacturers
ran everything through the switch, even the uplink, in recent years.
This will make things hard to fix.

> I went back to gig and set SQM to 50 megabit/s bidirectional and looking at
> tc qdisc -s eth0 I see ecn_mark 10339 on a single queue, none of the others
> have non-zero ecn_mark.

Yea, well, you need to use a diffserv enabled test to see marks or
drops in other queues.

Sort of my hope is that cake can run at 940mbit with software rate
limiting. But we probably need to find ways of parallizing the needed

>> I do not know why my linksys ac1200 build does not work. I generally
>> suspect it is because my big build server is getting ancient. Can you
>> send me your .config file for openwrt?
> http://swm.pp.se/aqm/wrt1200ac.config
> This was my first try, I haven't fine tuned it yet, but it works (boots and
> moves packets anyway :P )

Must be nice to win on the first try.

>> It would be VERY helpful if you pulled from ceropackages-3.14, and
>> added and built kmod-sched-cake and tc-adv and switched to using the
>> ceropackages feed also for luci-app-sqm and sqm-scripts. There are a
>> couple people here that would probably leap on that! :)
> I will give it a go in the next few days.
> --
> Mikael Abrahamsson    email: swmike at swm.pp.se

Dave Täht
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What will it take to vastly improve wifi for everyone?

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