Evolution of the standards for packet network synchronization

This article summarizes the work done by ITU-T Q13/15 over the last six years to standardize the transport of timing over packet networks. It provides a summary of the published documents in this area from ITU-T while providing some of the background that went into each document including the specification of synchronous Ethernet and IEEE 1588 telecom profiles. Finally, it provides insight into the future work on the transport of timing in packet networks in ITU-T Q13/15.