It's About Time: Why Your Network Needs an NTP Server
Dec 16, 2009, 12:33 (1 Talkback[s])
(Other stories by Paul Rubens)
"Running Your Own Stratum-1 Servers Stratum-1 time servers are
available in a single 1U rack-mountable form factor that can easily
be installed in your server room or data center and connected to
your network, and most have a way of connecting to a stratum-0
reference clock built in. The most commonly used ways to connect to
a stratum-0 device are by terrestrial radio or GPS signals.
"Terrestrial radio based connections use radio signals such as
WWVB out of Fort Collins, Colorado, MSF from Anthorn, UK, or DCF77
from Frankfurt, Germany. This is similar to the way consumer
devices such as watches and alarm clocks update themselves with
signals from reference clocks to keep accurate time.
"Statum-1 time servers that sync with GPS satellite signals are
more accurate, but are less convenient to install as they need to
be connected to an antenna fitted in a suitable position on the
roof of the building. Using time data from a number of satellites,
and by calculating the distance of each satellite from the antenna,
a stratum-1 time server that uses GPS reference clock signals is
able to get the precise time to within 50 or so nanoseconds."