QTech QSW-2800 series, Руководство по настройке

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Chapter 56 SNTP Configuration
56.1 Introduction to SNTP
The Network Time Protocol (NTP) is widely used for clock synchronization for global
computers connected to the Internet. NTP can assess packet sending/receiving delay in the
netwo
rk, and estimate the computer’s clock deviation independently, so as to achieve high
accuracy in network computer clocking. In most positions, NTP can provide accuracy from 1 to
50ms according to the characteristics of the synchronization source and network route.
Simple Network Time Protocol (SNTP) is the simplified version of NTP, removing the complex
algorithm of NTP. SNTP is used for hosts who do not require full NTP functions; it is a subset
of NTP. It is common practice to synchronize the clocks of several hosts in local area network
with other NTP hosts through the Internet, and use those hosts to provide time synchronization
service for other clients in LAN. The figure below depicts a NTP/SNTP application network
topology, where SNTP mainly works between second level servers and various terminals since
such scenarios do not require very high time accuracy, and the accuracy of SNTP (1 to 50 ms)
is usually sufficient for those services.
Working Scenario
Switch implements SNTPv4 and supports SNTP client unicast as described in RFC2030;
SNTP client multicast and unicast are not supported, nor is the SNTP server function.