nanog mailing list archives
Re: Cost effective time servers
From: Tom Beecher <beecher () beecher cc>
Date: Fri, 21 Jun 2019 11:50:35 -0400
This. I've had some timing issues ( unrelated to NTP ) with certain combinations of FlightAware RTLSDR USB sticks and Pi models. IIRC USB and Ethernet share the same bus on the Pis, and that can cause bumps. GPIOs run right off the SOC, avoiding that. On Fri, Jun 21, 2019 at 7:25 AM Denys Fedoryshchenko < nuclearcat () nuclearcat com> wrote:
On 2019-06-21 14:19, Niels Bakker wrote:* jay () west net (Jay Hennigan) [Fri 21 Jun 2019, 05:19 CEST]:On 6/20/19 07:39, David Bass wrote:What are folks using these days for smaller organizations, that need to dole out time from an internal source?If you want to go really cheap and don't value your time, but do value knowing the correct time, a GPS receiver with a USB interface and a Raspberry Pi would do the trick.Have you tried this? Because I have, and it's absolutely terrible. GPS doesn't give you the correct time, it's supposed to give you a good 1pps clock discipline against which you can measure your device's internal clock and adjust accordingly for drift due to it not being Cesium-based, influenced by room temperature etc. You're unlikely to get the 1pps signal across USB, and even then there'll likely be significant latencies in the USB stack compared to the serial interface that these setups traditionally use.I think it depends on recipe you are using. Raspberry have low latency GPIO, and some receivers have 1pps output. https://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html
Current thread:
- Cost effective time servers David Bass (Jun 21)
- Re: Cost effective time servers Mel Beckman (Jun 21)
- Re: Cost effective time servers Warren Kumari (Jun 21)
- Re: Cost effective time servers Mel Beckman (Jun 21)
- Re: Cost effective time servers Warren Kumari (Jun 21)
- Re: Cost effective time servers Warren Kumari (Jun 21)
- Re: Cost effective time servers Mel Beckman (Jun 21)
- Re: Cost effective time servers Jay Hennigan (Jun 21)
- Re: Cost effective time servers Niels Bakker (Jun 21)
- Re: Cost effective time servers Denys Fedoryshchenko (Jun 21)
- Re: Cost effective time servers Tony Finch (Jun 21)
- Re: Cost effective time servers Tom Beecher (Jun 21)
- Re: Cost effective time servers Niels Bakker (Jun 21)
- Re: Cost effective time servers Andy Ringsmuth (Jun 21)
- Re: Cost effective time servers Quan Zhou (Jun 24)
- Re: Cost effective time servers Joe Abley (Jun 24)
- Re: Cost effective time servers Jay Hennigan (Jun 24)
- Re: Cost effective time servers Chris Adams (Jun 24)
- Re: Cost effective time servers Forrest Christian (List Account) (Jun 24)
- Re: Cost effective time servers Chris Adams (Jun 24)
- Re: Cost effective time servers Forrest Christian (List Account) (Jun 24)
- Re: Cost effective time servers Eric S. Raymond (Jun 24)