simple network time protocol (Internet) (SNTP)

The Simple Network Time Protocol (SNTP) is a simple time server protocol used in embedded systems of automation technology and industrial control and in smaller networks for time transmissionand synchronization of server and client stations. It is a simplified variant of the Network Time Protocol( NTP) and allows simple, stateless operation via Remote Procedure Call( RPC).

The SNTP protocol can be transmitted in unicast, where a client sends a request to the unicast address of a specific time server. The client can derive the exact time from the server's response. Another transmission method is multicast, where the time server sends the time to a group of clients at regular intervals. And the third transmission option is based on a broadcast that a client sends to and that is received and answered by several time servers. In this type of transmission, the client identifies the time server that responded first and then works in unicast with this time server.

The Simple Network Time Protocol (SNTP) was specified by the Internet Engineering Task Force( IETF) and is described in RFC 2030.