Standardization of Low-Latency TCP with Explicit Congestion Notification: A Survey

Recent developments in networking have spurred the emergence of time-sensitive applications such as Web search, social networks, and the Industrial Internet. TCP, as the core networking protocol, implements reliable packet delivery for these applications. However, TCP isn't specifically optimized for timely packet delivery, so it has poor performance for time-sensitive scenarios. To counter this, the network research community has worked extensively on standards for reducing TCP's latency. Explicit Congestion Notification (ECN) is an extension to TCP/IP that's recommended for realizing low-latency TCP. This article surveys IETF standardization efforts for ECN-based solutions, and also proposes suggestions and future directions on this topic.