[time-nuts] Time illiterate query about feasibility of determining source clock quality based on NTP jitter/disp and offset

[Saku Ytti]

cisco#show ntp associations

      address         ref clock              st  when  poll reach
delay  offset    disp
*~meinberg-dhq    .PPS.                  1    13    256  377     2.6
 1.53     3.7
+~meinberg-lq      .PPS.                  1   131   256  377     2.1
 1.83     1.4
+~randomPC1      .GPS.                  1    29   256  377    17.0
1.35     0.3
+~randomPC2      randomPC3          2    45   256  377    17.6    1.17     0.3
+~randomPC3     .GPS.                   1    41   256  377    17.0
1.52     0.4
 * master (synced), # master (unsynced), + selected, - candidate, ~ configured


I see similar result all around, meinbergs which are lot closer, have
poorer offset
and disp.
Are there any conclusions I can draw from this?

Funny thing is that cisco iscloser to randomPC2 than its source random PC3,
so I think just based on that, I can determine I can't use these values to
determine quality of source clock?

But what would then explain how disp/jitter and offset are consistently better
towards the randomPC's which are considerably further down the network?

With basically no clue about time, I have two uneducated guesses.

1) meinberg is embedded hardware, software processing is slow in it
compared to randomPC which runs software much faster, which is
much more visible in NTP than actual clock quality

or

2) cisco and randomPC have similar clock hardware, something bulk
most hardware use, these clocks skew to same direction at relatively
similar rate, making the cisco and randomPC's having time quite close
to each other, both being bit further away from better clock.

Thanks,
-- 
  ++ytti