RFC 956

Algorithms for synchronizing network clocks, September 1985

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D.L. Mills

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DOI:  https://doi.org/10.17487/RFC0956

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This RFC discussed clock synchronization algorithms for the ARPA-Internet community, and requests discussion and suggestions for improvements. The recent interest within the Internet community in determining accurate time from a set of mutually suspicious network clocks has been prompted by several occasions in which errors were found in usually reliable, accurate clock servers after thunderstorms which disrupted their power supply. To these sources of error should be added those due to malfunctioning hardware, defective software and operator mistakes, as well as random errors in the mechanism used to set and synchronize clocks. This report suggests a stochastic model and algorithms for computing a good estimator from time-offset samples measured between clocks connected via network links. Included in this report are descriptions of certain experiments which give an indication of the effectiveness of the algorithms.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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