AES67 has made low-latency, synchronized, and uncompressed audio delivery commonplace on local area networks (LANs). As the need to provide two-way interaction between multiple sites rises, there is a desire to extend AES67 solutions into Wide Area Networks (WAN) and datacenters. This report examines the requirements and challenges when AES67 is extended beyond LAN environments. After describing the operational environments and associated constraints in detail, this report will address timing, transport and data reliability in the context of WAN and cloud. The report shows that none of the discussed environments is associated with a specific single problem, but instead, there are a number of smaller technical factors that interact and need to be addressed. While this study indicates that bit-precise transmission, synchronization and timing alignment is reasonably achievable, very low latencies, use of multicast, and 100% reliable reception remain challenging or impossible. Field experience annexes included in this report correlate well with the theoretical expectations based on this study. Robustness of AES67 is confirmed by its success on WAN production facilities and long-distance deployments. It brings generally better audio quality, latency performance and routing flexibility, compared to point-to-point transport based on lossy compression.
This document was developed in the SC-02-12-M task group on AES67 development under the leadership of Nicolas Sturmel.
Posted: Saturday, September 25, 2021