[Netalyzr] upstream buffering test

Brian J. Murrell brian at interlinx.bc.ca
Mon Feb 27 06:02:00 PST 2012


On 12-02-27 08:19 AM, Nicholas Weaver wrote:
> 
> Because its a deliberately crude test that only works on FIFO buffers:  It consists of a full rate UDP flow (it basically is in continual exponential ramp-up) which measures the increase in latency during the last 5 seconds of the 10 second test.

Can it not be made to more accurately reflect the actual situation then?

> If you did not have the active queueing, you would see 1s of latency, but since you have active queueing on the bottleneck buffer, this test reports the queue as being big (it is, for a single stream) but it doesn't affect the latency on your network under load.

Ultimately though netalyzer is making people thing they have a
bufferbloat problem when they don't, if I'm understanding all of this
correctly.

I just wonder if the test cannot be made to better reflect the
boatedness of the buffer in question so that people are not chasing ghosts.

Cheers,
b.

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