Jean-Loup Ferrant

Synchronous ethernet: a method to transport synchronization

This article discusses the evolving transport architecture, covering some of the synchronization distribution problems to many endpoints where mobile backhaul and TDM emulation occur. It shows how synchronous Ethernet fits into both the Ethernet and synchronization architectures, and discusses how this helped development in standardization bodies. Standardization allows the key building blocks of Ethernet silicon and specific timing devices to be developed, which allows a robust system implementation to be constructed while allowing interworking with and migration from existing SONET/SDH-based transport infrastructure. Finally, results are shown that indicate a very high level of performance is achievable with Synchronous Ethernet not subject to the normal packet delay variation and traffic load conditions that can occur in packet based networks.

Development of the first IEEE 1588 telecom profile to address mobile backhaul needs

This article describes the work performed by ITU-T SG15Q13 for defining the first telecom profile based on the use of IEEE Std 1588-2008. The first profile is specifically developed for the distribution of frequency using unicast IPv4 transmission, and required adaptation of the IEEE1588 protocol to make it suitable for the telecom environment. The objectives, reasons, and results of this adaptation are explained in this article. Since the distribution of phase/time is also gaining importance in telecom, the article briefly discusses the objectives, reasons, and upcoming work for the definition of another profile that will leverage other functions and clocks defined in IEEE1588.

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.