Performance Comparison of HTTP/3 and HTTP/2: Proxy vs. Non-Proxy Environments

This paper systematically evaluates the performance of QUIC/HTTP3 (H3) and TCP/HTTP2 (H2) protocols in proxy-enhanced environments. H3 leverages features such as UDP-based flow-controlled streams, integrated TLS, multiplexed connections, and connection migration, offering the potential for improved web communication. Despite extensive research, the impact of proxy integration and connection migration remains underexplored. This study addresses this gap by evaluating H3 and H2 across various scenarios, particularly in noisy networks and proxy setups. Our findings show that H3 excels under high loss and high latency conditions, significantly benefiting from its connection migration and multiplexing features, with improvements of up to 88.36% under high-loss and high-latency conditions, and 81.5% under extreme loss conditions, respectively. H3's connection migration remains robust, maintaining stable performance even in proxy-enhanced environments, ensuring seamless network transitions. The proxy has a more neutral impact on H3, while it significantly enhances H2 performance, particularly when paired with BBR, resulting in a 90% improvement in the single-stream file download experiment under severe network impairments. Any improvements observed in H3 under a proxy are minor and do not fundamentally alter H3's performance as they do for H2. Importantly, while H2 with the right congestion control algorithm (CCA) can achieve performance comparable to H3, H3's performance is more robust, as it is less impacted by network conditions, proxy settings, and CCA variations.