Design Considerations for Software Only Implementations of the IEEE 1588 Precision Time Protocol

This paper investigates adjusting computer clock frequency and time to provide a precise clock for test and measurement systems. In particular, it is concerned with the precision achievable using IEEE 1588 Precision Time Protocol systems without the support of specialized hardware. This paper outlines the design of a free IEEE 1588 implementation named PTPd. Particular attention is paid to the design of the clock servo—the system that steers the clock rate. This paper evaluates the implementation by the precision of the time coordination between networked test and measurement systems.