Aaron Gelter

New simulation and test results for IEEE 802.1AS timing performance

IEEE 802.1AS is a standard being developed in the 802.1 Working Group to provide precise timing and synchronization for bridged networks. It is one of the 802.1 Audio/Video Bridging (AVB) standards, and a major use of it will be to ensure that jitter, wander, and time synchronization requirements for time-sensitive applications in a residential AVB network are met. However, 802.1AS (and the other AVB standards) can be used in other applications as well. Each application will be specified by an ‘AVB profile’, and each profile will provide for very few options to simplify the configuration and operation by the user and result in low cost. IEEE 802.1AS includes an IEEE 802-specific layer-2 profile of IEEE Std. 1588TM - 2008; plus additional specifications to allow transport over 802.11 (WiFi), Ethernet PONs, and coordinated shared networks such as MoCA; plus additional requirements needed to ensure timing performance. IEEE 802.1AS is nearing completion, and is expected to be balloted by 4Q2009. This paper gives a brief overview of IEEE 802.1AS, focusing on recent developments. It then describes new simulation modeling and results for jitter, wander, and synchronization performance. Finally, it describes performance test results using 802.1AS bridges and end-stations.