Simple Network Time Protocol (SNTP) Overview

The Simple Network Time Protocol (SNTP) feature for Microsoft® Windows® CE .NET is derived from the Network Time Protocol (NTP). SNTP synchronizes the system time on a computer with that of a server that has been synchronized by a reference source such as a radio, satellite receiver, or modem. SNTP is used in scenarios that do not require or justify the high performance and accuracy of NTP.

SNTP can operate in unicast, multicast, and anycast modes. Windows CE supports unicast and multicast modes. A unicast client sends a request to a designated server at its unicast address and expects a reply from which it can determine the time and, optionally, the roundtrip delay, and the local clock offset relative to the server.

A multicast server periodically sends an unsolicited message to a designated IPv4 or IPv6 local broadcast address, or to a multicast group address. A multicast client listens on this address. The client generally sends no requests to the service, because it can get disrupted by untrusted SNTP or NTP multicast servers. You can prevent disruption by an untrusted server by using an access control mechanism to choose only the designated server known to, and trusted by, the client.

For more information about SNTP, see RFC 2030 at the Internet Engineering Task Force Web site.

Feature Summary

The following table shows operating system design information for SNTP.

Element Information
Dependencies Core Server Support (Services.exe)
Hardware considerations None

Modules and Components

The following table shows the components and modules that implement SNTP.

Item Module Component
Network Time Service timesvc None

Operating System Development Topics

SNTP Implementation Considerations

Configuring the SNTP Service

SNTP Registry Settings

See Also

Windows CE Modules and Components | Catalog Features

 Last updated on Friday, April 09, 2004

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