Netnod NTP services

A variety of industries require accurate time. Air traffic control, bank transactions and computer log file comparisons are examples of applications that rely on having an accurate time source. NTP is the protocol used on the Internet for synchronising computer system clocks.

Netnod’s Internet exchange points in Stockholm, COMIX (Malmö-Copenhagen), and Gothenburg are home to a total of six certified NTP time servers that are monitored by the SP Technical Research Institute of Sweden. Netnod offers services for synchronisation of computer clocks via the Internet using NTP, the standard protocol for time distribution over the Internet.

The Swedish National time scale is produced by the SP National Laboratory for Time and Frequency in Borås, and distributed using the NTP time servers operated by SP in Borås and by Netnod located at the Netnod Internet Exchange points in Stockholm, COMIX (Copenhagen-Malmö) and Gothenburg.

NTP time from the Swedish Netnod Internet Exchange servers is traceable back to the Swedish National time scale UTC (SP) by using GPS Common View measurements between the servers and the SP site in Borås, Sweden.

Netnod’s NTP servers together with SP’s servers in Borås are the only servers that distribute the Swedish National time scale and are traceable to UTC (sp).

In addition to the UTC(sp) over NTP, Netnod offers SDH stratum-1, 2.048 MHz services for synchronization to transport networks. This is delivered as an E1 interface, where the service is traceable to UTC(sp) in accordance to G.811. The system maintains local stability over 4 months. In the case of total failure of the local Cs standards, ITU-T G.812 SSU Type 3 will be maintained.