[time-nuts] A (slightly) different apu2 question

Wojciech Owczarek wojciech at owczarek.co.uk
Fri Nov 18 09:04:47 EST 2016


On 18 November 2016 at 09:21, Martin Burnicki <martin.burnicki at burnicki.net>
wrote:
>
> Just a few thoughts regarding NTP vs. PTP:
>


Oh dear... OK, before this snowballs into a bigger discussion this was not
meant to be:

My original post was _not_ about PTP vs. NTP, it was about the APU2 boards
and hardware timestamping.

My only point was to highlight the following:

1 This board has got exposed test pads for lots of 1PPS / frequency in /
out pins tied to timestamping hardware making it very easy to tap into
them. This is a great opportunity which begs to be exploited.

2. With a stable 1PPS from GPS or another source, this board can serve
nanosecond time, and that includes NTP in hardware, because the Intel NICs
can timestamp every packet, not just PTP. And yes, this mostly matters for
LAN.

I am fully aware of what you listed. NTP is just a different beast and
silicon vendors jumped onto PTP, and PTP inherently lacks the sophisticated
quorum and trust mechanisms NTP has, and yes, those are key items on the
P1588 WG agenda.

Thanks,
Wojciech

-- 
-

Wojciech Owczarek


More information about the time-nuts mailing list