Safety in DRL-Based Congestion Control: A Framework Empowered by Expert Refinement

Deep reinforcement learning (DRL) has been used in congestion control algorithms (CCAs) for its ability to adapt to different network environments. However, its effectiveness is often hindered by the limited availability of training data and constrained training scales. While it has been proved that combining rule-based (expert) CCAs as a guide for DRL (namely hybrid CCAs) can address this limitation, we show through experimental measurements that rule-based CCAs potentially restrict action exploration of DRL models and may cause the DRL models to overly rely on them for higher reward gains. To address this gap, this paper proposes Marten, a framework that improves the effectiveness of rule-based CCAs for DRL. Marten’s key innovations include an entropy-based dynamic exploration scheme that expands the exploration of DRL, and a reward adjustment scheme to prevent the DRL models’ over-reliance on experts in hybrid CCAs. We have implemented Marten in both simulation platform OpenAI Gym and deployment platform QUIC. Experimental results in both emulated and production networks demonstrate Marten can improve throughput by 0.31% and reduce latency by 12.69% on average compared to the state-of-the-art hybrid CCAs. Compared to BBR, Marten achieves a 2.79% increase in throughput and an 11.73% reduction in latency on average.