NTP service

This service aims at providing one or more time reference points of high precision. The limited time accuracy of network devices requires synchronization at regular intervals with a precise time reference. The setting of the network devices’ clocks is using NTP protocol (Network Time Protocol). NTP service (which is provided by more than one synchronized servers) is retrospectively synchronized to the national time standard UTC (Universal Time Coordinate) / GMT (Greenwich Mean Time), from which EET (European Eastern Time), EEST (European Eastern Summer Time) arise, which is the national time standard used in Greece.

GRNET operates a synchronization source Stratum 0 device with GPS. The device is connected to the LAN Ethernet router. The transmission time of the NTP message is very small (~ 0.1 msec) and is usually chosen by the router in Athens for synchronization. Alongside GRNET used as alternative sources of synchronization channels canon.inria.fr ( and rolex.switch.ch (

Users of the service

The NTP service is aimed at all connected GRNET peers that need a high accuracy source of time. They can use the NTP protocol to synchronize their network devices.