Time Distribution Model

Network time distribution systems use a hierarchical time distribution model, as shown in this figure:

Stratum 0

GPS

Satellites or NMI Dial-Up Service

Stratum 1

Symmetricom

SyncServer

Stratum 2

SyncServers

or Computer

Systems

(NTP Clients)

Stratum 3

Computer

Systems

(NTP

Clients)

Figure 2-1:The S100 in the Time Distribution Hierarchy

In hierarchical systems, primary time source clocks are Stratum 0 (zero), including GPS satellites, National Institute of Standards and Technology (NIST) ACTS dial-up service, or similar national time standards organizations.

The S100 acts as a Stratum 1 time server that derives its time from GPS and distributes this time over a TCP/IP network using NTP. Stratum 2 NTP clients can distribute time to Stratum 3 computers.

How the S100 Works

The following describes how the S100 acquires and secures time.

S100 User Guide – Rev. D – June 2005

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Symmetricom manual Time Distribution Model, How the S100 Works