Improve MPTCP with SDN: From the perspective of resource pooling

Abstract Multipath TCP (MPTCP) is proposed by IETF to support concurrent multipath transmission between multihomed hosts. Resource pooling principle, which treats network as a single pooled resource, is applied in the design of MPTCP schemes, and provides guidelines for MPTCP's control to achieve resource utilization and fair resource allocation. However, randomized routing solution and load balancing without global network information in MPTCP have become obstacles to achieve these objectives, which is validated through our measurements. To address above problems, we propose S-MPTCP, which realizes coupling control to MPTCP connections in network based on SDN technology providing global network information. Leveraging collected topology information, a key parameter, expected throughput, is calculated for each subflow ensuring the efficiency and fairness in resource exploration and allocation, and according to it, routing and load balancing modules are improved. Under S-MPTCP's control, subflow's throughput will stabilize around its expected throughput, and meanwhile congestion can be alleviated effectively. Experimental results show that S-MPTCP achieves significant enhancement of bandwidth utilization and fair resource allocation, and the time needed for load balancing is shortened considerably.