Fast and smooth data delivery using MPTCP by avoiding redundant retransmissions
Yigit Ozcan, Fabrice M. Guillemin, Patrice Houze, Catherine Rosenberg · 2017
We introduce a new, simple, yet effective scheme for reducing the impact of receiver buffer blocking in Multipath TCP (MPTCP). This blocking primarily occurs when the paths have different characteristics. This phenomenon is due to the limited size of the MPTCP receiver buffer. In a nutshell, our scheme allows, under certain conditions, the retransmission of a segment by a different interface than the one used originally and the closure of the badly behaving TCP connection. Our scheme anticipates the problem by opening multiple TCP connections for each interface, but only uses one at a given time. It detects when a segment needs to be retransmitted from another interface, closes the ongoing connection on the original interface, and starts using one of the backup connections. We show through NS3 simulations that our scheme improves MPTCP goodput, with a gain of 19% compared to other MPTCP schemes, and provides a smooth data delivery to the application layer. This last feature is of utmost importance for streaming applications. Furthermore, while other MPTCP schemes fail to perform better than the best single path TCP for some scenarios, our proposed scheme always outperforms the best single path TCP.