Subject: [aqm] quick comment on aqm-eval-guidelines

From: Dave Taht <[email-masked]>
Date: Fri, 3 Jul 2015 11:55:25 -0700

"   From each of these sets of measurements, the 10th and 90th
   percentiles and the median value SHOULD be computed.  For each
   scenario, a graph can be generated, with the x-axis showing the end-
   to-end delay and the y-axis the goodput.  This graph provides part of
   a better understanding of (1) the delay/goodput trade-off for a given
   congestion control mechanism, and (2) how the goodput and average
   queue size vary as a function of the traffic load."

This is lame. Capturing *all* the data as in a CDF or an Winstien
ellipsis plot, across the entire range, is to be preferred when
engineering a system.

90th percentile is a very, very low bar to cross, most of the nasty
bufferbloat happens at the top end of the range. Packet crcs, as one
example, are measured out to what, one in 6 million? Would you drive a
car that had the steering wheel fail one time in 10 turns?

as for medians, seven figure summaries, if you must...

-- 
Dave Täht
worldwide bufferbloat report:
http://www.dslreports.com/speedtest/results/bufferbloat
And:
What will it take to vastly improve wifi for everyone?
https://plus.google.com/u/0/explore/makewififast

---

From: Nicolas Kuhn <[email-masked]>
Date: Mon, 6 Jul 2015 10:35:15 +0200

Hi Dave, 

Thank you for your comment. 

> On 03 Jul 2015, at 20:55, Dave Taht <[email-masked]> wrote:
> 

We have updated the above paragraph from : 
“ 
 From each of these sets of measurements, the 10th and 90th
 percentiles and the median value SHOULD be computed.  For each
 scenario, a graph can be generated, with the x-axis showing the end-
 to-end delay and the y-axis the goodput.  This graph provides part of
 a better understanding of (1) the delay/goodput trade-off for a given
 congestion control mechanism, and (2) how the goodput and average
 queue size vary as a function of the traffic load.
"

to 

“
  From each of these sets of measurements, the CDF of the considered
  metrics SHOULD be computed.  For each scenario, the following graph
  may be generated: the x-axis shows the end-to-end delay, the y-axis
  the goodput and ellipses are computed such as detailed in [WINS2014].
  This graph provides part of a better understanding of (1) the delay/
  goodput trade-off for a given congestion control mechanism, and (2)
  how the goodput and average queue size vary as a function of the
  traffic load.

 […]

  [WINS2014]
             Winstein, K., "Transport Architectures for an Evolving
             Internet", PhD thesis, Massachusetts Institute of
             Technology , 2014.  

"

Kind regards,

Nicolas 

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