This topic describes the Time-Provider Interface (TPI) for DCE Distributed Time Service software. The topic provides a brief overview of the TPI, explains how to use external time-providers with DTS, and describes the data structures and message protocols that make up the TPI.
Coordinated Universal Time (UTC) is widely used and is disseminated throughout the world by various standards organizations. Several manufacturers supply devices that can acquire UTC time values via radio, satellite, or telephone. These devices can then provide standardized time values to computer systems. Normally, one device is connected to a computer system; the device runs a process that interprets signals and translates them to time values, which can either be displayed or be provided to the server process running on the connected system.
To synchronize its system clock with UTC using an external time-provider device, a DTS server needs a software interface to the device to periodically obtain UTC. In effect, this interface serves as an intermediary between the DTS server and external time-provider processes. The DTS server requires the interface to obtain UTC time values and to determine the associated inaccuracy of each value. The interface between the DTS server process and the time-provider process is called the Time-Provider Interface.
The remainder of this topic describes the TPI and its attendant processes in detail. The following topic describes the control flow between the DTS server process, the TPI, and the time-provider process.