On 21/05/2015 17:21, Jonathan Morton wrote:

      

        
On 19 May, 2015, at 22:17, Dave Taht <dave.taht@gmail.com> wrote:

So I finished writing up my thoughts on bobbie,
http://www.bufferbloat.net/projects/codel/wiki/Bobbie

which might work better than anything on the table in the face of huge
bursts like these, when the rate differential is so small.


      

      
I wonder if there’s any profit in making fq_codel and cake behave more like a policer on ingress; that would be halfway to bobbie without writing a lot of new code.

A reasonable test would be to try configuring fq_codel with interval = target = 5ms.  If that works better, I could add similar functionality to cake.

- Jonathan Morton

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    Up for a challenge I tried it.  Line rate is 40000 down, 10000 up -
    Sky broadband UK VDSL2 PTM (manual overhead of 8 for VLAN tagging on
    WAN & VDSL2 flags)

    note that I also use ECN everywhere.  From the dslreports site, with
    a new layout I note - nice!  Numbers at end of each line are

    reported latency for idle (minimum), up (average), down (average) in
    ms.

    

      Baseline:

      fq_codel 37500 9700 interval 100ms
      http://www.dslreports.com/speedtest/526382 - 109 114 112

      fq_codel 37500 9700 interval 5ms  
      http://www.dslreports.com/speedtest/526367 - 106 119 111

      

      

      fq_codel 38500 9700 interval 100ms
      http://www.dslreports.com/speedtest/526318 - 106 120 110 standing
      q but managed slightly better than....

      fq_codel 38500 9700 interval 5ms  
      http://www.dslreports.com/speedtest/526305 - 116 142 118 standing
      q

      

      

      fq_codel 39000 9700 interval 100ms
      http://www.dslreports.com/speedtest/526335 - 110 153 113 spikey
      spaced

      fq_codel 39000 9700 interval 5ms  
      http://www.dslreports.com/speedtest/526308 - 109 194 112 spikey
      closer

      

      

      fq_codel 40000 9700 interval 100ms
      http://www.dslreports.com/speedtest/526347 - 116 191 118 spikey 

      fq_codel 40000 9700 interval 5ms  
      http://www.dslreports.com/speedtest/526353 - 109 172 112 spikey

      

    I don't think tweaking intervals has given the hoped for
    result in my case.  If anything It looks like it increases standing
    latency though some of graph

    scaling makes that difficult to see.  The final test looks like it's
    heading in a better direction but it still has 420+ms spikes.

    

    

    
-- 
Thanks,

Kevin@Darbyshire-Bryant.me.uk