Multipath TCP algorithms : theory and design

The congestion control schemes used by Multipath TCP have been designed based on earlier theoretical work. The current implementation in the Linux kernel supports two congestion control schemes : Coupled RFC 6356 and OLIA [Khalili2012] . Several other multipath congestion control schemes have been proposed and it is likely that the quest for the best multipath congestion control scheme will continue in the coming years.

In [Peng2013] , Qiuyu Peng and his colleagues propose a theoretical analysis of several multipath TCP congestion schemes and compares them based on ns-2 simulations. The theoretical analysis considers three criteria :

  • TCP Friendliness or is the congestion control scheme fair compared with regular TCP (NewReno in this case RFC 5681)
  • Responsiveness or how quickly can the congestion control scheme can adapt to changing network conditions
  • Window Fluctuations

The second criteria is very interesting because real traffic is more bursty than the large file transfers that are used to evaluate congestion control schemes by simulations.

Four existing congestion control schemes are compared with a newly proposed one in [Peng2013] . Unfortunately, the paper only considers early multipath congestion control schemes that predate RFC 6356 and does not compare the proposed algorithm with OLIA [Khalili2012] . Considering OLIA and perhaps other congestion control schemes and analyzing more complex simulations would be a useful extension to this work.


[Khalili2012](1, 2) Ramin Khalili, Nicolas Gast, Miroslav Popovic, Utkarsh Upadhyay, and Jean-Yves Le Boudec. 2012. MPTCP is not pareto-optimal: performance issues and a possible solution. In Proceedings of the 8th international conference on Emerging networking experiments and technologies (CoNEXT ‘12). ACM, New York, NY, USA, 1-12.
[Peng2013](1, 2) Qiuyu Peng, Anwar Walid, and Steven H. Low. 2013. Multipath TCP algorithms: theory and design. In Proceedings of the ACM SIGMETRICS/international conference on Measurement and modeling of computer systems (SIGMETRICS ‘13). ACM, New York, NY, USA, 305-316.