{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T11:10:25Z","timestamp":1779361825137,"version":"3.51.4"},"reference-count":37,"publisher":"Association for Computing Machinery (ACM)","issue":"3","license":[{"start":{"date-parts":[[2019,12,17]],"date-time":"2019-12-17T00:00:00Z","timestamp":1576540800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"funder":[{"name":"Singapore NRF","award":["R-252-000-638-121"],"award-info":[{"award-number":["R-252-000-638-121"]}]}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["Proc. ACM Meas. Anal. Comput. Syst."],"published-print":{"date-parts":[[2019,12,17]]},"abstract":"<jats:p>In 2016, Google proposed and deployed a new TCP variant called BBR. BBR represents a major departure from traditional congestion-window-based congestion control. Instead of using loss as a congestion signal, BBR uses estimates of the bandwidth and round-trip delays to regulate its sending rate. The last major study on the distribution of TCP variants on the Internet was done in 2011, so it is timely to conduct a new census given the recent developments around BBR. To this end, we designed and implemented Gordon, a tool that allows us to measure the exact congestion window (cwnd) corresponding to each successive RTT in the TCP connection response of a congestion control algorithm. To compare a measured flow to the known variants, we created a localized bottleneck where we can introduce a variety of network changes like loss events, bandwidth change, and increased delay, and normalize all measurements by RTT. An offline classifier is used to identify the TCP variant based on the cwnd trace over time. Our results suggest that CUBIC is currently the dominant TCP variant on the Internet, and it is deployed on about 36% of the websites in the Alexa Top 20,000 list. While BBR and its variant BBR G1.1 are currently in second place with a 22% share by website count, their present share of total Internet traffic volume is estimated to be larger than 40%. We also found that Akamai has deployed a unique loss-agnostic rate-based TCP variant on some 6% of the Alexa Top 20,000 websites and there are likely other undocumented variants. The traditional assumption that TCP variants \"in the wild\" will come from a small known set is not likely to be true anymore. We predict that some variant of BBR seems poised to replace CUBIC as the next dominant TCP variant on the Internet.<\/jats:p>","DOI":"10.1145\/3366693","type":"journal-article","created":{"date-parts":[[2019,12,18]],"date-time":"2019-12-18T13:21:11Z","timestamp":1576675271000},"page":"1-24","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":82,"title":["The Great Internet TCP Congestion Control Census"],"prefix":"10.1145","volume":"3","author":[{"given":"Ayush","family":"Mishra","sequence":"first","affiliation":[{"name":"National University of Singapore, Singapore, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiangpeng","family":"Sun","sequence":"additional","affiliation":[{"name":"National University of Singapore, Singapore, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atishya","family":"Jain","sequence":"additional","affiliation":[{"name":"Indian Institute of Technology, Delhi, Delhi, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sameer","family":"Pande","sequence":"additional","affiliation":[{"name":"Indian Institute of Technology, Delhi, Delhi, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raj","family":"Joshi","sequence":"additional","affiliation":[{"name":"National University of Singapore, Singapore, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ben","family":"Leong","sequence":"additional","affiliation":[{"name":"National University of Singapore, Singapore, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2019,12,17]]},"reference":[{"key":"e_1_2_1_1_1","volume-title":"Proceedings of PFLDnet .","author":"Baiocchi Andrea","year":"2007"},{"key":"e_1_2_1_2_1","volume-title":"Peterson","author":"Brakmo Lawrence S.","year":"1994"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1145\/3009824"},{"key":"e_1_2_1_4_1","volume-title":"Soheil Hassas Yeganeh, and Van Jacobson","author":"Cardwell Neal","year":"2017"},{"key":"e_1_2_1_5_1","volume-title":"Ian Swett, Victor Vasiliev, Priyaranjan Jha, Yousuk Seung, Matt Mathis, and Van Jacobson.","author":"Cardwell Neal","year":"2019"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1016590112381"},{"key":"e_1_2_1_7_1","volume-title":"Passive TCP Identification for Wired and Wireless Networks: A Long-Short Term Memory Approach . arXiv preprint:1904.04430","author":"Chen Xiaoyu","year":"2019"},{"key":"e_1_2_1_8_1","unstructured":"Yuchung Cheng Neal Cardwell Nandita Dukkipati and Priyaranjan Jha. 2019. RACK: a time-based fast loss detection algorithm for TCP . IETF Draft. (2019). https:\/\/datatracker.ietf.org\/doc\/html\/draft-ietf-tcpm-rack-05  Yuchung Cheng Neal Cardwell Nandita Dukkipati and Priyaranjan Jha. 2019. RACK: a time-based fast loss detection algorithm for TCP . IETF Draft. (2019). https:\/\/datatracker.ietf.org\/doc\/html\/draft-ietf-tcpm-rack-05"},{"key":"e_1_2_1_9_1","volume-title":"Lin","author":"Comer Douglas E.","year":"1994"},{"key":"e_1_2_1_10_1","unstructured":"DARPA. 1981. Internet Protocol. RFC 791. (1981).  DARPA. 1981. Internet Protocol. RFC 791. (1981)."},{"key":"e_1_2_1_11_1","doi-asserted-by":"crossref","unstructured":"Sally Floyd. 2003. HighSpeed TCP for Large Congestion Windows . RFC 3649. (2003).  Sally Floyd. 2003. HighSpeed TCP for Large Congestion Windows . RFC 3649. (2003).","DOI":"10.17487\/rfc3649"},{"key":"e_1_2_1_12_1","first-page":"216","article-title":"TCP Veno: TCP Enhancement for Transmission over Wireless Access Networks","volume":"21","author":"Fu Cheng Peng","year":"2006","journal-title":"IEEE JSAC"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1145\/1400097.1400105"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1109\/ACCESS.2018.2833107"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICNP.2017.8117540"},{"key":"e_1_2_1_16_1","unstructured":"Alexa Internet Inc. 2018. The Top 500 websites on the Internet. (2018). https:\/\/www.alexa.com\/topsites  Alexa Internet Inc. 2018. The Top 500 websites on the Internet. (2018). https:\/\/www.alexa.com\/topsites"},{"key":"e_1_2_1_17_1","volume-title":"Nandita Dukkipati and Matt Mathis","author":"Jerry Chu Yuchung Cheng","year":"2013"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1145\/956981.956989"},{"key":"e_1_2_1_19_1","volume-title":"Proceedings of PFLDnet .","author":"Leith Douglas","year":"2005"},{"key":"e_1_2_1_20_1","volume-title":"Proceedings of VALUETOOLS .","author":"Liu Shao"},{"key":"e_1_2_1_21_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICC.2016.7510785"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1145\/1064413.1064418"},{"key":"e_1_2_1_23_1","volume-title":"Proceedings of ATC .","author":"Netravali Ravi","year":"2015"},{"key":"e_1_2_1_24_1","volume-title":"libnetfilter_queue. (2019). https:\/\/bit.ly\/2HimY17","author":"Netfilter Organization"},{"key":"e_1_2_1_25_1","volume-title":"Proceedings of SIGCOMM .","author":"Padhye Jitendra","year":"2001"},{"key":"e_1_2_1_26_1","unstructured":"Vern Paxson and Mark Allman. 2009. TCP Congestion Control . RFC 5681. (2009).  Vern Paxson and Mark Allman. 2009. TCP Congestion Control . RFC 5681. (2009)."},{"key":"e_1_2_1_27_1","unstructured":"Brien Posey. 2019. Explore the Cubic congestion control provider for Windows. (2019). https:\/\/bit.ly\/2VfhxoA  Brien Posey. 2019. Explore the Cubic congestion control provider for Windows. (2019). https:\/\/bit.ly\/2VfhxoA"},{"key":"e_1_2_1_28_1","unstructured":"GNU Project. 2019. wget. (2019). https:\/\/www.gnu.org\/software\/wget  GNU Project. 2019. wget. (2019). https:\/\/www.gnu.org\/software\/wget"},{"key":"e_1_2_1_29_1","doi-asserted-by":"publisher","DOI":"10.1145\/3131365.3131370"},{"key":"e_1_2_1_30_1","unstructured":"Canada Sandvine Inc. Waterloo ON. 2018. The 2018 Global Internet Phenomena Report. (2018). https:\/\/www.sandvine.com\/phenomena  Canada Sandvine Inc. Waterloo ON. 2018. The 2018 Global Internet Phenomena Report. (2018). https:\/\/www.sandvine.com\/phenomena"},{"key":"e_1_2_1_31_1","volume-title":"Proceedings of ICC .","author":"Sun W."},{"key":"e_1_2_1_32_1","doi-asserted-by":"publisher","DOI":"10.1109\/INFOCOM.2006.188"},{"key":"e_1_2_1_33_1","doi-asserted-by":"publisher","DOI":"10.1145\/3355369.3355604"},{"key":"e_1_2_1_34_1","unstructured":"David X Wei Cheng Jin Steven H Low and Sanjay Hegde. 2007. FAST TCP. IEEE\/ACM Transactions on Networking.  David X Wei Cheng Jin Steven H Low and Sanjay Hegde. 2007. FAST TCP. IEEE\/ACM Transactions on Networking."},{"key":"e_1_2_1_35_1","volume-title":"Proceedings of INFOCOM .","author":"Xu Lisong","year":"2004"},{"key":"e_1_2_1_36_1","doi-asserted-by":"publisher","DOI":"10.1109\/TNET.2013.2278271"},{"key":"e_1_2_1_37_1","doi-asserted-by":"publisher","DOI":"10.1109\/GLOCOMW.2011.6162434"}],"container-title":["Proceedings of the ACM on Measurement and Analysis of Computing Systems"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3366693","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/3366693","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,17]],"date-time":"2025-06-17T23:44:38Z","timestamp":1750203878000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3366693"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,12,17]]},"references-count":37,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2019,12,17]]}},"alternative-id":["10.1145\/3366693"],"URL":"https:\/\/doi.org\/10.1145\/3366693","relation":{},"ISSN":["2476-1249"],"issn-type":[{"value":"2476-1249","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,12,17]]},"assertion":[{"value":"2019-12-17","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}