A record-based retransmission policy on SCTP´s Concurrent Multipath Transfer

Concurrent Multipath Transfer (CMT) uses the SCTP´s multi-homing feature to distribute data across multiple end-to-end paths in a multi-homed SCTP association in order to achieving a more benefit cumulative throughput. Using CMT to transfer content-rich streaming media in the Ad hoc network will result in loss rate occurred and changed frequently on paths, and then the loss data need be retransmitted via a certain retransmission strategy. There are five retransmission strategies addressed for destination selecting in CMT. But in the current five retransmission strategies, paths´ previous statuses are omitted during selecting destination for retransmission. In fact, paths´ historical status can play an import role for paths selecting. In this paper, an improved scheme named RTX_LR is proposed based on paths´ historical timeout records. And the average throughput is used as measure metric as well. A demonstrate using simulation is provided showing how receiver buffer (rbuf) blocking is reduced, and average throughput of a rbuf- constrained CMT association could benefit from proposed scheme.