ICTEAM - Public Thesis defense - Jawad Manzoor

Dissecting HTTP/2 and QUIC : Measurement, Evaluation and Optimization

The Internet is evolving from the perspective of both usage and connectivity. New web and transport protocols such as HTTP/2 and QUIC have been developed in recent years to handle the complex modern web content and ensure users’ QoE regardless of the technology they use to connect to the Internet and despite variations in the quality of users’ Internet connectivity.

However there is a lack of sufficient understanding and evaluation of these new protocols across a range of environments, which opens new opportunities for research in this direction.

This thesis provides a comprehensive study on the behavior, usage and performance of HTTP/2 and QUIC, and advances them by implementing several optimizations. First, we study the

behavior of HTTP/1 and HTTP/2 traffic using datasets of passive measurements collected in various operational networks and develop a machine learning-based method for the classification of encrypted web traffic into appropriate HTTP versions. Next, we show with the

help of emulations that HTTP/2 exhibits poor performance in adverse scenarios such as under high packet losses or network congestion and implement an optimization in Chromium browser to make it more robust in such scenarios.

Finally, we collect and analyze QUIC and TCP traffic in a production wireless mesh network.

Our results show that while QUIC outperforms TCP in fixed networks, it exhibits significantly lower performance when there are WiFi links in the end-to-end path. To see why this is the case, we carefully examine how delay variations which are common in wireless networks

impact the congestion control and loss detection algorithms of QUIC. We also explore the interaction of QUIC transport with the advanced link layer features of WiFi such as frame aggregation. We optimize QUIC based on our findings and show notable increase in performance.

Jury members :

• Prof. Ramin Sadre (UCLouvain), supervisor
• Prof. Llorenç Cerdà-Alabern (UPC, Spain), supervisor
• Prof. Charles Pecheur (UCLouvain), chairperson
• Prof. Olivier Bonaventure (UCLouvain), secretary
• Prof. Vicent Plà (UPV, Spain)
• Prof. Oliver Hohlfeld (B-TU, Germany)