Evaluation of multipath TCP load sharing with coupled congestion control option in heterogeneous networks

The evolution of technologies, particularly the emergence of multi-interface terminals (3G, WLAN, WMAN, etc), totally changes the vision of services offered to users in the future. Multi-homing and multipath transmission support becomes more and more indispensable to satisfy user demands. Multipath TCP (MPTCP) is a modified version of Transmission Control Protocol (TCP) which allows using simultaneously multiple paths for data transmission. It aims to improve the throughput of TCP connection in a manner that a MPTCP connection over multiple paths should achieve at least a no worse throughput than a single TCP connection over the best constituent path. In a previous work, we have evaluated the load sharing of MPTCP without the coupled congestion control option. In this paper, the couple congestion control of MPTCP is enabled. The measurement results show that MPTCP with coupled congestion control provides a better performance. However, the heterogeneous networks environment (Ethernet, Wifi and 3G) still has a great impact on MPTCP throughput and reveals the need of an intelligent algorithm for interface selection in MPTCP.