The cost of variability

Abstract

We explore the robustness of synchronization performed in the presence of variable latencies using two software clocks: the TSCclock, designed to replace ntpd for Internet synchronisation, and ptpd, a software implementation of IEEE-1588. Using a precise comparison methodology the TSCclock is shown to be more accurate and far more robust. We discuss the reasons why and the implications for IEEE-1588 more generally.