nanog mailing list archives
Re: NIST NTP servers
From: Laszlo Hanyecz <laszlo () heliacal net>
Date: Fri, 13 May 2016 14:40:10 +0000
On 2016-05-13 14:12, Lamar Owen wrote:
On 05/11/2016 09:46 PM, Josh Reynolds wrote:maybe try [setting up an NTP server] with an odroid?...You really have to have at least a temperature compensated quartz crystal oscillator (TCXO) to even begin to think about an NTP server, for anything but the most rudimentary of timing.
There are WWVB clocks that try to sync nightly. Many of them don't even have a second indicator, but they give reliable time to the minute. NTP is a lot better than this as it continuously disciplines the clock instead of just lining it up once a day, but we're talking about doing this over the internet where we measure latency in milliseconds. If you're working down at the picosecond level you will probably not be using NTP to distribute your clock signal. Running an NTP client against pool servers is a lot better than not running it at all, but running it against a fancy local server with a GPSDO hooked up to it is only marginally better than the pool servers.
It all depends on what you want to do but a cheap ARM or Intel Atom computer works well for an NTP server (remember millisecond level accuracy). If you can afford to build a secure bunker with armed guards and redundant everything for your time server that's good, but a few RPi style computers with GPS hats are almost as good, and you can buy a lot of them for very little money..
-Laszlo
Current thread:
- Re: NIST NTP servers, (continued)
- Re: NIST NTP servers Leo Bicknell (May 11)
- Re: NIST NTP servers Brandon Vincent (May 11)
- Re: NIST NTP servers Jon Meek (May 11)
- Re: NIST NTP servers Josh Reynolds (May 11)
- Re: NIST NTP servers Lamar Owen (May 13)
- Re: NIST NTP servers Mel Beckman (May 13)
- Re: NIST NTP servers Lamar Owen (May 13)
- Re: NIST NTP servers Mel Beckman (May 13)
- Re: NIST NTP servers Mel Beckman (May 13)
- Re: NIST NTP servers Lamar Owen (May 14)
- Re: NIST NTP servers Laszlo Hanyecz (May 13)
- Re: NIST NTP servers Chuck Anderson (May 13)
- Re: NIST NTP servers Sharon Goldberg (May 13)
- RE: NIST NTP servers John Souvestre (May 12)
- Re: NIST NTP servers Chris Adams (May 12)
- RE: NIST NTP servers John Souvestre (May 12)
- RE: NIST NTP servers Chuck Church (May 11)
- Re: NIST NTP servers George Herbert (May 12)
- RE: NIST NTP servers Allan Liska (May 11)
- RE: NIST NTP servers Chuck Church (May 10)