Re: [Linuxptp-devel] [PATCH RFC 0/6] Improve accuracy with software timestamping

[Miroslav L. <mli...@re...>]

On Tue, Mar 10, 2015 at 10:29:43AM +0100, Miroslav Lichvar wrote:
> To give you an idea what difference you can expect with raw
> delay/offset and weights, here are graphs from a simulation with
> 10us jitter and default PI constants with SW timestamping.
> 
> https://mlichvar.fedorapeople.org/tmp/ptp/ptp4l_error.png
> 
> The RMS time error improved from 2.71 us to 1.85 us and 1.46 us. The
> RMS frequency error improved from 1.08 ppm to 0.73 ppm and 0.53 ppm.

And here is a simulation where every 100th packet is delayed by 1
millisecond to better show the effect of sample weighting.

https://mlichvar.fedorapeople.org/tmp/ptp/ptp4l_error2.png

-- 
Miroslav Lichvar