What Does Simple Network Time Protocol Mean?
Simple Network Time Protocol (SNTP) is a simplified version of Network Time Protocol (NTP) that is used to synchronize computer clocks on a network. This simplified version of NTP is generally used when full implementation of NTP is not needed.
Techopedia Explains Simple Network Time Protocol
SNTP is a simplified access strategy for servers and clients using NTP. SNTP synchronizes a computer’s system time with a server that has already been synchronized by a source such as a radio, satellite receiver or modem.
SNTP supports unicast, multicast and anycast operating modes. In unicast mode, the client sends a request to a dedicated server by referencing its unicast address. Once a reply is received from the server, the client determines the time, roundtrip delay and local clock offset in reference to the server. In multicast mode, the server sends an unsolicited message to a dedicated IPv4 or IPv6 local broadcast address. Generally, a multicast client does not send any requests to the service because of the service disruption caused by unknown and untrusted multicast servers. The disruption can be avoided through an access control mechanism that allows a client to select a designated server he or she knows and trusts.