When you configure the i5/OS® operating system as an SNTP server, your system acts as a time server for other devices.
Other SNTP clients check time by polling your SNTP server. If a client's time values do not match the SNTP server time, a time adjustment begins. The client's system time is adjusted until the required time value is reached. This is useful for maintaining time within a network.
In Figure 1, System A is configured as the SNTP server. In this situation, the Coordinated Universal Time (UTC) is retrieved from System A rather than being synchronized with an external time source. This internal time value is sent to all SNTP client systems (System B and Client A) that are connected to System A.
In addition to using the SNTP server to synchronize clocks in the network, you can concurrently run your system as an SNTP client to obtain time from an outside time source. For an example, see Scenario: Synchronizing clocks with i5/OS.