[Cerowrt-devel] Torrents are too fast

[Sebastian Moeller]

Hi Dane,


On Nov 20, 2014, at 15:13 , Dane Medic <dm70dm at gmail.com> wrote:

> dpreed, thank you for response. I'm already using fq_codel with cerowrt and I don't think it does what I want (or maybe I want too much :)
> 
> So the steps I've made:
> flashed wndr3700v2 with cerowrt 3.10.50-1 then I've measured:
> 
> root at cerowrt:/usr/lib/CeroWrtScripts# sh betterspeedtest.sh -p wlan-si.net -t 120
> 2014-11-20 12:18:34 Testing against netperf.bufferbloat.net (ipv4) with 5 simultaneous sessions while pinging wlan-si.net (120 seconds in each direction)
> .........................................................................................................................
>  Download:  3.78 Mbps
>   Latency: (in msec, 119 pings, 0.00% packet loss)
>       Min: 13.077 
>     10pct: 251.522 
>    Median: 317.851 
>       Avg: 308.497 
>     90pct: 371.033 
>       Max: 376.132
> ............................................................................................................................
>    Upload:  0.48 Mbps
>   Latency: (in msec, 103 pings, 0.00% packet loss)
>       Min: 12.278 
>     10pct: 12.727 
>    Median: 18.359 
>       Avg: 23.256 
>     90pct: 33.971 
>       Max: 180.303
> 
> Then I've put these commands:
> 
> uci set sqm.ge00.enabled=1
> uci set sqm.ge00.download=3200
> uci set sqm.ge00.qdisc=nfq_codel
> uci commit sqm
> reboot
> 
> And another measure:
> 
> root at cerowrt:/usr/lib/CeroWrtScripts# sh betterspeedtest.sh -p wlan-si.net -t 120
> 2014-11-20 12:49:05 Testing against netperf.bufferbloat.net (ipv4) with 5 simultaneous sessions while pinging wlan-si.net (120 seconds in each direction)
> .........................................................................................................................
>  Download:  2.74 Mbps
>   Latency: (in msec, 121 pings, 0.00% packet loss)
>       Min: 12.210 
>     10pct: 13.002 
>    Median: 15.077 
>       Avg: 15.095 
>     90pct: 16.968 
>       Max: 18.599
> .............................................................................................................................
>    Upload:  0.49 Mbps
>   Latency: (in msec, 101 pings, 0.00% packet loss)
>       Min: 12.255 
>     10pct: 12.684 
>    Median: 16.679 
>       Avg: 23.100 
>     90pct: 34.019 
>       Max: 170.173
> 
> The tests doesn't look bad, but the problem is I watch a video clip on youtube and my sister starts torrent client, I can't watch anymore.

	Could you post the content of /etc/config/sqm from after activating SQM please. It looks like you did not activate shaping on egress (its not in the “ici set *” above and the upload statistics look identical to the first unshaped example). You really need to control the buffer in both directions to get rid of nasty latency spikes (especially with torrents that I assume  will try to use both directions maximally if left to their own devices). Also 4M/512K sounds like a DSL link, if so you might find the link layer adjustments helpful (if there are question what to fill in just ask). Also if you have a linux or macosx computer available I would recommend to install netperf-wrapper and use the RRUL test to simultaneously load down- and up-link (or alternatively netperfrunner.sh) as this will show bloated buffers more clearly than the individual tests for each direction as performed by betterspeedtest.sh.

Best Regards
	Sebastian


> 
> Cheers
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel