Predictably reliable real-time transport over large bandwidth-delay product networks

Abstract:

Today’s dominant Internet transport protocol-TCP-is known to achieve a low bandwidth utilization on large bandwidth-delay product network paths. As such paths become common in the Internet, TCP’s inefficiency will be the main bottleneck in deploying high-rate, low-latency communications services such as tele-presence, free-viewpoint video or virtual reality. In this paper, we present PRRT-Predictably Reliable Real-time Transport, a protocol layer that efficiently supports these services. PRRT is based on hybrid error correction that allows for both proactive and reactive reliability mechanisms. Specifically, it is designed to achieve the optimal trade-off between those mechanisms under strict delay constraints. We describe key features of the architecture: adaptive block-erasure coding and predictable reliability achieved by statistical performance modeling. We also evaluate PRRT’s performance on a range of high bandwidth-delay product paths under a service-specific delay.