Hi Justin,

The newest Speed Test is great! It is more convincing than I even thought it 
would be. These comments are focused on the "theater" of the measurements, so 
that they are unambiguous, and that people can figure out what's happening

I posted a video to Youtube at: http://youtu.be/EMkhKrXbjxQ to illustrate my 
points. NB: I turned fq_codel off for this demo, so that the results would be 
more extreme.

1) It would be great to label the gauge as "Latency (msec)" I love the term 
"bufferbloat" as much as the next guy, but the Speed Test page should call the 
measurement what it really is. (The help page can explain that the latency is 
almost certainly caused by bufferbloat, but that should be the place it's 
mentioned.)

2) I can't explain why the latency gauge starts at 1-3 msec. I am guessing that 
it's showing incremental latency above the nominal value measured during the 
initial setup. I recommend that the gauge always show actual latency. Thus the 
gauge could start at 45 msec (0:11 in the video) then change during the 
measurements.

3) I was a bit confused by the behavior of the gauge before/after the test. I'd 
like it to change only when when something else is moving in the window. Here 
are some suggestions for what would make it clearer:
        - The gauge should not change until the graph starts moving. I found it 
confusing to see the latency jump up at 0:13 just before the blue download 
chart started, or at 0:28 before the upload chart started at 0:31.
        - Between the download and upload tests, the gauge should drop back to 
the nominal measured values. I think it does.
        - After the test, the gauge should also drop back to the nominal 
measured value. It seems stuck at 4928 msec (0:55).

4) I like the way the latency gauge changes color during the test. It's OK for 
it to use the color to indicate an "opinion". Are you happy with the thresholds 
for yellow & red colors?

5) The gauge makes it appear that moderate latency - 765 msec (0:29) - is the 
same as when the value goes to 1768 msec (0:31), and also when it goes to 4,447 
msec (0:35), etc. It might make more sense to have the chart's full-scale at 
something like 10 seconds during the test. The scale could be logarithmic, so 
that "normal" values occupy up to a third or half of scale, and bad values get 
pretty close to the top end. Horrible latency - greater than 10 sec, say - 
should peg the indicator at full scale.

6) On the Results page (1:20), I like the red background behind the latency 
values. I don't understand why the grey bars at the right end of the chart are 
so high. Is the latency still decreasing as the queue drains? Perhaps the ping 
tests should run longer until it gets closer to the nominal value.

This is such a great tool. Thanks!

Rich
_______________________________________________
Bloat mailing list
[email protected]
https://lists.bufferbloat.net/listinfo/bloat

Reply via email to