Forward Error Correction and Weighted Hierarchical Fair Multiplexing for HTTP/3 over QUIC

Web applications are ubiquitous and increasingly use HTTP/3. Their performance is affected by the underlying QUIC transport protocol. An important performance metric is the transmission delay impacted by the standardized loss recovery and resource prioritization. To improve the robustness against packet loss, we extend QUIC's recovery mechanism by the convolutional Forward Error Correction scheme Tetrys. For better control over the order of sent data, we use a round-robin scheduler that provably ensures hierarchical max-min fairness of the multiplexed streams at a byte-granular level. We extend its functionality to support strict priorities within a scheduling tree of weighted classes, integrating it into the Extensible Prioritization Scheme for HTTP/3. Measurements of a prototype implementation demonstrate that transmission delays improve under common web workloads and that the scheduler delivers important assets earlier with the newly specified parameters.