K wrote:
Hi,
What are some good ways to get time?
I know about NTP v3 and v4 and use it on some systems. I need a time
accuracy of < 1 ms.
NTP over gigabit Ethernet is down to what time of precision? 1ms? Does
anyone have any data on this?
I know that the linux os is compiled for something like 1 ms precision
IRIG is a pain? Is there anything better?
Thanks in advance
I'm running two Sun Ultra 10 workstations in my home. Sunblok runs
Solaris 8 and ntpd 4.0 with a Motorola Oncore M12+T GPS receiver as a
hardware reference clock. Sunblok is my ntp server. It is connected to
Sunbitch (Solaris 9, ntpd 4.0) via 100mb full duplex switched Ethernet.
ntptime on Sunbitch reports an estimated error of 71 us. It also
reports a maximum error of 128,000 us or 128 ms. I believe the maximum
error represents a theoretical worst case rather than meaning the local
clock was actually off by 128 ms at any recent time.
So it can be done. I think that the Motorola GPS has a great deal to
do with it. If Sunblok were synchronized to the best available
internet servers instead of a hardware reference clock, its local clock
would be much less stable. 10 ms is about the best accuracy I would
expect from a client synchronized to a server that synchronized over the
internet.
Success will also depend on the hardware and O/S running on the client.
_______________________________________________
questions mailing list
[email protected]
https://lists.ntp.isc.org/mailman/listinfo/questions
