Abstract
The last three decades have seen much evolution in web and network protocols: amongst them, a transition from HTTP/1.1 to HTTP/2 and a shift from loss-based to delay-based TCP congestion control algorithms. This paper argues that these two trends come at odds with one another, ultimately hurting web performance. Using a controlled synthetic study, we show how delay-based congestion control protocols (e.g., BBR and CUBIC + Hybrid Slow Start) result in the underestimation of the available congestion window in mobile networks, and how that dramatically hampers the effectiveness of HTTP/2. To quantify the impact of such finding in the current web, we evolve the web performance toolbox in two ways. First, we develop Igor, a client-side TCP congestion control detection tool that can differentiate between loss-based and delay-based algorithms by focusing on their behavior during slow start. Second, we develop a Chromium patch which allows fine-grained control on the HTTP version to be used per domain. Using these new web performance tools, we analyze over 300 real websites and find that 67% of sites relying solely on delay-based congestion control algorithms have better performance with HTTP/1.1.
Original language | English (US) |
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Title of host publication | CoNEXT 2020 - Proceedings of the 16th International Conference on Emerging Networking EXperiments and Technologies |
Publisher | Association for Computing Machinery, Inc |
Pages | 364-370 |
Number of pages | 7 |
ISBN (Electronic) | 9781450379489 |
DOIs | |
State | Published - Nov 23 2020 |
Event | 16th ACM Conference on Emerging Networking Experiment and Technologies, CoNEXT 2020 - Barcelona, Spain Duration: Dec 1 2020 → Dec 4 2020 |
Publication series
Name | CoNEXT 2020 - Proceedings of the 16th International Conference on Emerging Networking EXperiments and Technologies |
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Conference
Conference | 16th ACM Conference on Emerging Networking Experiment and Technologies, CoNEXT 2020 |
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Country/Territory | Spain |
City | Barcelona |
Period | 12/1/20 → 12/4/20 |
Funding
Acknowledgements. We thank Pradeep Dogga and the anonymous CoNEXT reviewers for their valuable feedback. This work was partially supported by NSF grant CNS-1943621.
Keywords
- HTTP
- TCP
- congestion control algorithm
- protocol design
- web performance
ASJC Scopus subject areas
- Computer Networks and Communications