Network Architecture

We are currently running Sonoma D12 NTP servers, each connected to a differential GPS antenna on the roof and each with a rubidium oscillator to provide a stable clock in the event of an issue with the GPS signal.

Each is capable of handling 10000 qps, and an explanation of how many clients they can support is given in NTP Server Load.


The four servers operate independantly and are not actively synchronised to each other. They use their internal GPS and rubidium oscillator as their only time source.

Host names

The four servers are called ntp[1-4] The host names that we ask you to access them by p[1-4] and s[1-4] are CNAMEs that we use to enable us to introduce more servers with different characteristics at a later stage without mucking people around. Rules on which names to use are given the in the Acceptable use policy.


  • ntp1 is in Albany connected via FX.
  • ntp2 is in Auckland CBD connected via ICONZ.
  • ntp3 is in Wellington CBD connected via FX.
  • ntp4 is in Christchurch connected via 2Degrees.

Software and Standards

As far as we know the software is the standard NTPv4 distribution which support the latest version of the NTP protocol (v3) and the Simple Network Time Protocol (SNTPv4).

Future plans

We are in touch with an NZ University that is developing a wire speed NTP server. When that eventuates we hope to add those servers as front ends to the current servers, taking a 1PPS signal from them, and possibly swap over the rubidium oscillators.

At some point we may buy more servers to add to the network. Two more would good but that is not high priority for us.

Ideally we would like a pair of active hydrogen masers, possibly five or more caesium clocks, a special basement to house them and a satellite dish for TWSTFT but given the cost of those we can only dream.