Microchip (Microsemi) network time servers

Computer networks – Time synchronisation to the nearest millisecond using the NTP protocol. A time server receives the exact time directly from cesium and rubidium atomic clocks located on GPS satellites and transmits it to the computers on a network. 

Thus it may be ensured that the clocks of all computers on a network always show the same time.  In the event the GPS signal should be interrupted, a high-precision clock located on the server (a special quartz or rubidium oscillator) kicks in to provide the exact time.