Overview of Stream-Aware Scheduling for QUIC-Based Proxying Using Multiple Paths

In 3GPP networks, Access Traffic Steering, Switching, and Splitting (ATSSS) is specified to enable network-assisted use of multiple paths based on a multipath-enabled QUIC tunnel. Using multiple paths can introduce packet reordering because of path asymmetry, loss, and differing delays. Packet reordering may be mistaken for congestion and thus lead to unnecessary reductions in throughput. While various packet-based schedulers have been proposed to address these issues, stream-aware concepts have not been widely explored when multiple end-to-end flows use the same tunnel. In this paper, we present our scheduling framework that supports stream-aware scheduling and compare state-of-the-art packet-based schedulers to stream-aware approaches in the multipath tunnel scenario, with particular focus on the Bandwidth-Limited Application Demand Estimating (BLADE) scheduler. Our results show that stream-aware scheduling concepts mitigate reordering and improve throughput in this scenario. This paper provides an overview of the current state of stream-aware scheduling for proxy scenarios. Future work is necessary and should investigate stream-aware techniques, adapt packet-based schedulers to be stream-aware, and propose novel stream-aware schedulers.