Modeling MultiPath TCP for Control Parameter Tuning

MultiPath TCP (MP-TCP) allows the use of multiple paths between two end hosts for a single data transmission, extending the capabilities of SinglePath Transmission Control Protocol (SP-TCP). AIMD congestion control algorithm can be implemented on each subpath of the MP-TCP sender. However, the characteristics of the AIMD-type window flow control depend on the control parameters (α, β). There have been some guidelines proposed to select proper control parameters (α, β) that can achieve fair bandwidth sharing between SP-TCP and MP-TCP senders using existing MP-TCP congestion algorithms. However, current guidelines do not offer a solution that can simultaneously increase the throughput of an MP-TCP sender and ensure fairness between MP-TCP and SP-TCP senders. To address this issue, this study proposes a control parameter setting for an MP-TCP sender that can maximize the sender’s throughput and ensure fairness between SP-TCP and MP-TCP senders. We derive a fluid model of a network that includes SP-TCP and MP-TCP senders, describing the relationship between control parameters, the aggregate throughput of an MP-TCP sender, and the packet loss rate of a router.