On 3/7/06, Richard B. Gilbert <[EMAIL PROTECTED]> wrote: > > Bill Myers wrote: > > I have questions regarding best practices on architecture of NTP > subnets. > > I've thoroughly read "Notes on Setting up a NTP subnet" from the NTP > sites. > > > > Is there a need for multiple external time source TECHNOLOGIES. That > is, is > > it sufficient to use multiple (8) GPS receivers with ACTS dial backup > > and Rubidium clocks? This is a sizeable investment for the > infrastructure, > > but is it the right way? Is it necessary or desirable to have other > sources > > such as radio and/or Internet? > > > > In case you have not picked up on it, I'm talking about an appliance > here. > > I find it odd that one cannot NTP peer these appliances. This suggests > to > > me that we should create a stratum 2 tier peer layer a stratum 3 tier > that > > peers and serves time to the endpoints. > > > > More dysfunction? The plan is for the stratum 2 tier, which is also the > > time distribution tier, to be the cache DNS for some high-volume data > center > > environments. > > _______________________________________________ > > questions mailing list > > [email protected] > > https://lists.ntp.isc.org/mailman/listinfo/questions > > > > It depends strongly on your needs for correct time and reliability. You > have not really specified your requirements. Are you serving a single > site or multiple sites? How far can your time deviate from UTC? How > much money are your willing and able to spend? > > If you absolutely must have sub millisecond accuracy and 100 percent > reliability then you need to allow for: > 1. Failure of a reference clock (GPS receiver) > 2. Failure of the GPS System (insane satellites, jamming of GPS > frequencies, etc.) > 3. Failure of one or more of your lowest stratum servers. > 4. Things neither you nor I have thought of or can think of! > > So tell us more and maybe we can give you better advice.
Reliability and synchronization is most important. <10 millisecond accuracy is probably sufficient. Large financial with 100's of locations. International. Has experienced financial loss due to NTP failure. ~Bill _______________________________________________ > questions mailing list > [email protected] > https://lists.ntp.isc.org/mailman/listinfo/questions > _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
