¶ Technical overview
Netnod is the leading provider of time services in the Nordics. With fully redundant clock nodes located all over Sweden, Netnod Time offers the most precise, secure and robust time available today.
This document provides the technical overview of Netnod’s premium time services which include our PTP service, Netnod Time Direct and Netnod Time Remote. We also provide a free Network Time Protocol (NTP) and Network Time Security (NTS) service.
Netnod’s time services use state-of-the-art technology and redundant time nodes distributed across Sweden. Our time services, which are easy to set up and use, provide the most cost-effective way to ensure your network time is accurate, robust and avoids the risks associated with using only GNSS.
Read more about the risks of relying on GNSS and how ISO27001 compliance requires redundant time.
¶ Swedish National Time
Netnod works with RISE, the national laboratory responsible for the Swedish national timescale (UTC(SP)), and is trusted by PTS and RISE to distribute Swedish national time. Netnod’s time service is constantly monitored and checked internally and by PTS and RISE. This means that we can guarantee that Netnod's clocks are always traceable to Swedish national time.
You can read more about Swedish Distributed Time Service here.
¶ Precision time
The Netnod Time system is designed to maintain PRTC-A accuracy (+/- 100ns from the reference) for at least 3 months of isolation. Our reference is Swedish local time, UTC(SP), provided by RISE. This time is, normally, within a couple of nanoseconds from the global time reference UTC.
Netnod’s clocks rarely differ more than +/-10ns from Swedish local time. The precision in our current calibration (static phase error compared to UTC(SP)) is better than +/- 20ns.
¶ Netnod clock nodes
Our state-of-the-art time nodes use caesium clocks distributed in redundant pairs throughout Sweden to ensure redundancy.
There are six time nodes in different locations in Sweden, each continuously monitored and steered to follow UTC(SP). To ensure high availability, every time node is equipped with two atomic clocks generating separate time scales.
¶ Netnod as primary or secondary time source
Our recommendation is to always use time from two sources, where Netnod can/should be the primary source and time from another source the secondary.