IEEE ratifies IEEE 802.3bf for Ethernet support of time distribution and synchronization protocols

The IEEE has ratified IEEE 802.3bf-2011, a new amendment to its 802.3 Ethernet standard that will help enable hardware support such time distribution and synchronization protocols as IEEE 1588 and IEEE 802.1AS-2011 over packet networks. Time distribution and synchronization is essential in such hot applications as mobile backhaul, audio and video distribution systems, and smart grid applications.

IEEE 802.3bf-2011, ratified on May 16, provides an Ethernet physical layer (PHY) agnostic support of time distribution and synchronization protocols, while minimizing changes to existing Ethernet PHYs and maintaining the layering rules of Ethernet transport. It should spur adoption of IEEE 802.1 Audio/Video Bridging (AVB) protocol technologies, the organization believes.

“The audio and video communities have been using Ethernet technologies for years as a high-performance, low-cost transport. IEEE 802.3bf-2011 and the IEEE 802.1 AVB protocol suite allow for precise timing across the network -- a critical function for delivery of high-quality audio and video in real time. For the first time, this can be accomplished using interoperable IEEE 802 technologies, rather than many proprietary and incompatible solutions,” said Steve Carlson, chair of the IEEE 802.3bf Task Force, and president, High Speed Design, Inc.

The new specifications should find use across a wide variety of networks, the IEEE believes.

“The open and scalable nature of the solution specified in IEEE 802.3bf-2011 fits very well into the specific nature of Ethernet networks. We are especially excited about the outlook of using this technology in Ethernet Passive Optical Networks [EPONs], where hardware support for time-of-day distribution and synchronization protocols is of key importance for mobile backhauling, video distribution applications, as well as Metro Ethernet centric business services,” said Marek Hajduczenia, Ph.D, chief editor for IEEE 802.3bf-2011 and xPON Standardization Director for ZTE Corp. “The ratification of this standard, its rapid development and PHY agnostic character clearly demonstrate the dominance of Ethernet as the packet technology of choice for existing and future networks, no matter what the end application is.”

The IEEE’s work received support from those active in other standards bodies. Said Patrick Diamond, Ph.D, member of the ITU-T SG15 Q13 study group and senior director of systems engineering at Semtech Corp. said, “With many networked applications requiring sub-microsecond time synchronization, standards bodies (ITU-T for example), have struggled to identify mechanisms that can meet this requirement. The creation of IEEE 802.3bf established (for the first time) a standardized means to determine exactly when an Ethernet frame is ingressing or egressing a port. This starting and ending ‘time’ point exact knowledge is the catalyst for highly accurate ‘residence’ time measurements for packets traversing Ethernet nodes. This measurement capability is critical to delivering ‘Time and Frequency’ over packet networks to those application endpoints demanding sub-microsecond time and sub-10ppb frequency accuracy.”

The approved draft is available for purchase at http://www.techstreet.com/ieee/cgi-bin/detail?vendor_id=4759.