TY - GEN
T1 - Mind the delay
T2 - 16th ACM Conference on Emerging Networking Experiment and Technologies, CoNEXT 2020
AU - Agarwal, Neil
AU - Varvello, Matteo
AU - Aucinas, Andrius
AU - Bustamante, Fabián
AU - Netravali, Ravi
N1 - Funding Information:
Acknowledgements. We thank Pradeep Dogga and the anonymous CoNEXT reviewers for their valuable feedback. This work was partially supported by NSF grant CNS-1943621.
Publisher Copyright:
© 2020 Owner/Author.
PY - 2020/11/23
Y1 - 2020/11/23
N2 - 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.
AB - 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.
KW - HTTP
KW - TCP
KW - congestion control algorithm
KW - protocol design
KW - web performance
UR - http://www.scopus.com/inward/record.url?scp=85097629143&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85097629143&partnerID=8YFLogxK
U2 - 10.1145/3386367.3431299
DO - 10.1145/3386367.3431299
M3 - Conference contribution
AN - SCOPUS:85097629143
T3 - CoNEXT 2020 - Proceedings of the 16th International Conference on Emerging Networking EXperiments and Technologies
SP - 364
EP - 370
BT - CoNEXT 2020 - Proceedings of the 16th International Conference on Emerging Networking EXperiments and Technologies
PB - Association for Computing Machinery, Inc
Y2 - 1 December 2020 through 4 December 2020
ER -