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Re: Throughput riddle

On 03/20/2016 06:10 AM, Celejar wrote:
On Fri, 18 Mar 2016 18:01:58 -0700
David Christensen <dpchrist@holgerdanske.com> wrote:
Perhaps the NAS has an automatic crossover feature on it's Gigabit port.
   If you do a computer-cable-computer test, you will want a (category
5E) crossover cable.

If they weren't doing crossover, wouldn't I be doing a lot worse, or

Richard Hector clarified that crossover cables are only required for 10 and 100 Mbps.

But, I still recommend Category 5E cables.

It's not clear if you are doing an apples-to-apples comparison.  Perhaps
iperf isn't measuring what you think it is.

That's exactly what I'm asking: what is iperf measuring, and why is it
so much lower than the speedtest throughput? My understanding is that
it simply measures straight-up TCP (or UPD, if desired) throughput.
Even allowing for protocol overhead at the various network stack
layers, the deviation shouldn't be that great.

Perhaps you can find information on the project site (?):


None of your devices are running the firmware or OS the manufacturer
intended for it.  Perhaps you should revert the router and/or NAS, and
test again.

1) The current situation is acceptable, and I'd rather run what I'm
running at my current speeds than revert to the manufacturers'
firmwares and OSs.

2) Intellectual curiosity is primarily what's driving me to understand
my numbers.

3) If there's really something wrong with the OSS code, I should be
filing bugs.

Assuming you've looked for error/ warning messages everywhere and haven't seen anything obvious, the next step would seem to be enabling or adding verbosity/ logging/ debugging/ etc., starting with iperf on one end and ending with iperf on the other end.


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