A fluid model of multipath TCP algorithm: Fairness design with congestion balancing

Multipath TCP (MP-TCP) algorithms are supposed to be fair to single-path TCP and utilize multiple paths to support high quality end-to-end services. Existing MP-TCP algorithms in literature are confronted with the problems: 1) MP-TCP can be excessively aggressive towards single-path TCP in their coexisting environments; 2) they sometimes fail to balance congestion on multiple paths; 3)their performance is prone to degradation under the circumstances of path heterogeneity, wireless network environments and bandwidth-intensive applications. In this paper, we propose a fluid-based MP-TCP algorithm to address the above problems. Our algorithm has a unique stable equilibrium and serves the design goals of fairness and congestion-balancing. Simulation results show that our algorithm achieves improvement of TCP-friendliness and window fluctuation performance in different scenarios.