The Weak Convergence of TCP Bandwidth Sharing
TCP is the dominating transmission protocol in the Internet since decades. It proved its flexibility to adapt to unknown and changing network conditions. A distinguished TCP feature is the comparably fair resource sharing. Unfortunately, this abstract fairness is frequently misinterpreted as convergence towards equal sharing rates. In this paper we show in theory as well as in experiment that TCP rate convergence does not exist. Instead, the individual TCP flow rate is persistently fluctuating over a range close to one order of magnitude. The fluctuations are not short term but correlated over long intervals, such that the carried data volume converges rather slowly. The weak convergence does not negate fairness in general. Nevertheless, a particular transmission operation could deviate considerably.
KeywordsTCP Congestion Resource sharing Fairness Convergence
This work has been funded in part by the German Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research) in scope of project SASER under grant No. 16BP12200.
- 1.Jacobson, V.: Congestion avoidance and control. In: Proceedings of the SIGCOMM 1988 (1988)Google Scholar
- 3.Podlesny, M., Gorinsky, S.: Multimodal Congestion Control for Low Stable-State Queuing. Technical Report WUCSE-2006–41, August 2006. http://openscholarship.wustl.edu/cse_research/192
- 6.Padhye, J., Firoiu, V., Towsley, D., Kurose, J.: Modeling TCP throughput: A simple model and its empirical validation. In: Proceedings of the ACM SIGCOMM, 1998, pp. 303–314 (1998)Google Scholar
- 7.Lautenschlaeger, W.: A Deterministic TCP Bandwidth Sharing Model, April 2014. http://arxiv.org/abs/1404.4173
- 8.Handbook Teletraffic Engineering, ITU-D Study Group 2 Question 16/2 (2008)Google Scholar
- 9.Bogoiavlenskaia, O.: Markovian Model of Internetworking Flow Control, Kalashnikov Memorial Seminar, Petrozavodsk, Инфopмaциoнныe пpoцeccы, 2.2 (2002)Google Scholar
- 12.McKenney, P.E.: Stochastic fairness queueing. In: Proceedings of the INFOCOM 1990 (1990)Google Scholar
- 13.Briscoe, R.: Re-feedback: Freedom with Accountability for Causing Congestion in a Connectionless Internetwork, Diss. UC London (2009). http://www.bobbriscoe.net/projects/refb/refb_dis.pdf
- 14.Braden, R. (ed.) Requirements for Internet Hosts - Communication Layers, IETF, RFC 1122 (1989)Google Scholar
- 15.Allman, M.: TCP Congestion Control with Appropriate Byte Counting (ABC), IETF, RFC 3465 (2003)Google Scholar
- 16.Hemminger, S.: tcp: remove Appropriate Byte Count support (2013). https://github.com/torvalds/linux/commit/ca2eb5679f8ddffff60156af42595df44a315ef0
- 17.Allman, M., Paxson, V., Blanton, E.: TCP Congestion Control, IETF, RFC 5681 (2009)Google Scholar