Concurrent multipath transfer under delay-based dissimilarity using SCTP

Concurrent multipath transfer using the stream control transmission protocol (CMT-SCTP) enables multi-interface devices to send data simultaneously over multiple paths. The multipath transfer requires special handling in real life practice due to the different path characteristics, such as a path using 4G and a path using Wi-Fi. Moreover, for smartphones and other portable devices, the resources, such as the sender and receiver buffer are limited due to the short battery life. The buffer resource is common for all paths when working with the CMT-SCTP. In this paper, we have evaluated the performance of CMT-SCTP under the dissimilarity between the paths caused by the propagation delay with a common and a split buffer. We have applied the buffer splitting (CMT-RTTA) based on the round trip time (RTT), so that the paths with longer RTT (slow paths) occupy less buffer resource both at sender and receiver. In order to enhance the transmission throughput, we have also scheduled the transmissions based on the RTT value to the corresponding destination address. For the evaluation, the experiments are performed on a two-path and a four-path network. CMT-RTTA performs as good as the basic CMT-SCTP over a simple two-path setup, whereas, on a complex four-path setup, CMT-RTTA outperforms the CMT-SCTP.