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NTP [Network Time Protocol]

Unit 4, 2-8 South St

Rydalmere, NSW 2116

T: 13 14 91

F: 1800 659 025

W: www.simplextime.com.au

NTP definition & Application

Document: NTP.doc Issued: October 2008

Q: What is SNTP?

A: Simple Network Time Protocol (SNTP) is a simplified version of NTP Protocol, that is

used for less time critical end use devices.

SNTP uses the same packet format as NTP but does NOT compensate for the transmission

delay between the SNTP device and the connected NTP server.

Assuming the NTP server side can maintain reasonably accurate time, then the inherent

transmission delay on the local network between the SNTP Client and the local NTP Server is

reasonably negligible

SNTP Client devices that can only display time to the nearest second should not experience

any noticeable delay as the expected delay induced by SNTP clients would be under 500

milliseconds (this is an average value and not for every case).

It is essential to have a hierarchy of NTP server for strata 0 - n of the network to maintain

highly accurate time, and only use SNTP clients at strata n+1.

If the SNTP client connected to the local NTP Server is on a reasonably fast or light traffic

network then the delay between SNTP client requests and NTP server responses will be

minimal, and as such time received at the SNTP device will be contain only slight errors.

Note:

1. If the local TCP/IP network experiences high traffic or happens to be a slow network, then

the delay experienced from the time of the NTP time packet transmission and its receipt at the

SNTP client will affect the overall time accuracy at the SNTP client device.

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