Windows time synchronization is Microsoft Corporation’s implementation of the standard Windows SNTP w32time. This method is also referred to as unicast synchronization. With this form of time synchronization, all routers manage User Datagram Protocol (UDP) traffic.
If the Site Director is a Metasys Server, the server maintains system time and broadcasts this time to all subordinate network engines. You configure Windows time synchronization by accessing the Clock and Region settings under the Control Panel of the server's operating system. There you set the Date and Time parameters to retrieve the time automatically, which enables the Network Time Protocol (NTP) service on the computer. In this configuration, time comes from a reliable time server that is accessible on the customer's network or over the Internet. The NTP service on the Metasys Server must be on; if NTP is off, the Metasys Server cannot retrieve time from the time server, and the network engines are not able to retrieve time from the Metasys Server.
If the Site Director is a network engine, system time also comes from an external time server that is accessible on the building network or over the Internet. As the site time server, the engine provides the time zone, date, and time for all other engines on the site. All other devices are considered time clients because they receive the time zone, date, and time from the Engine Site Director. In this configuration, the Device Time Servers attribute under the Focus window of the Engine's Site object specifies the IP address or host name of the external time server. The Device Time Servers attribute under each subordinate network engine specifies the IP address or host name of the Engine Site Director.
There is yet a third selection for Windows time synchronization. You can set up the Metasys Server and each network engine to retrieve the time on their own from an external time server. This configuration is not as desirable because every supervisory device in the Metasys system is making separate time requests to the same time server and the devices might be using different time sync periods. In this configuration, the Device Time Servers attribute under the Focus window of the Metasys Server and all of its engines specifies the IP address or host name of the external time server.