Symmetricom manual S100 Technology, S100 Product Overview, Sources of Time, On the Network

Chapter 2

S100 Technology

Overview

This chapter gives a review of the S100 technology.

There is additional information in “S100 Specifications” on page 119.

S100 Product Overview

The S100 network time server synchronizes secure network time. The following sections describe this technology.

Sources of Time

The S100 obtains time from GPS, ACTS, or another S100, and delivers it to computers and other devices on a network. It acquires UTC (Universal Coordinated Time) from GPS signals, or using ACTS dial-up to the National Institute of Standards and Technology (in the U.S.). If there are several S100s on your network, only a few S100s need acquire UTC directly. They can then distribute that time to other S100s.

On the Network

Clients on a network synchronize with a time source using NTP, the Network Time Protocol, to exchange packets of time. The S100 implements NTP Version 4. This prevents intruders from spoofing time packets and using NTP to gain access to your systems. Unlike previous versions, NTP Version 4 implements asymmetric encryption. This is the same technique used

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