[LEAPSECS] internet drafts about zoneinfo

[Ian Batten]

> 

> As I have said many times, in theory POSIX time is a form of TAI, being a constant offset from TAI, but in practice (for those who care enough to buy the hardware), POSIX Time is whatever GPS distributed NTP say it is.



Is that right?  Looking at a nearby Stratum-2 reference (on a large university campus), I see a wide range of sources.  PPS could be anything there's a driver for, of course, but the UK Janet and LINX Stratum 1s include MSF for UTC(MSF), USNO I presume means a radio source of UTC(USNO), CTD I think is an Italian radio source for UTC(IEN).  This looks like a Stratum 2 that's aligned to a variety of independent sources of UTC, which are then synchronised by whatever mysterious means are used keeping UTC coherent.

ian


> xtick.uh.edu     .GPS.            1 u  453 1024  377   174.04  -12.605    0.27

> .usno.pa-x.dec.c .USNO.           1 u   33 1024  377   151.95   -0.971    0.43

> -ntp-sop.inria.f .GPS.            1 u  564 1024  377    28.03   -1.394    0.06

> -ntp1.linx.net   .PPS.            1 u   41   64  377     9.26    0.103    0.09

> -ntp0-p.ja.net   .MSF.            1 u  875 1024  377     9.99   -1.533    0.35

> -ntp0.linx.net   .PPS.            1 u    8   64  377     9.32    0.077    0.55

> *ntp0.inrim.it   .CTD.            1 u   48   64  377    35.71   -0.035    0.09

> -ntp2.linx.net   .GPS.            1 u    1  128  377     8.91   -0.326    0.26

> .tick.ucla.edu   .GPS.            1 u  754 1024  377   184.19    2.133    2.67

>  webmail-dz19.si 0.0.0.0         16 u    - 1024    0     0.00    0.000 16000.0

> .tock.usno.navy. .USNO.           1 u  199 1024  377   137.50    4.232    1.56

> .ntp2.usno.navy. .USNO.           1 u  467 1024  377   142.82    4.710    1.59

> -ntps1-0.cs.tu-b .PPS.            1 u   18 1024  377    39.47    0.242    0.21

> +ntps1-1.cs.tu-b .PPS.            1 u   54   64  377    37.86   -0.063    0.70

> -ntp1.inrim.it   .CTD.            1 u   25   64  377    34.93   -0.096    0.05

> +ntp2.inrim.it   .CTD.            1 u   29   64  377    35.48   -0.037    0.12

> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://six.pairlist.net/pipermail/leapsecs/attachments/20110305/da072f66/attachment.html>