Applying TCP-Friendly Congestion Control to Concurrent Multipath Transfer

The steadily growing importance of Internet-based applications and their resilience requirements lead to a rising number of multi-homed sites. The idea of Concurrent Multipath Transfer (CMT) is to exploit the existence of multiple paths among endpoints to increase application data throughput. However, handling the congestion control of each path independently lacks of fairness against non-CMT flows. In this paper, we describe our approach of combining CMT with the idea of Resource Pooling (RP) in order to achieve a performance improvement over non-CMT transfer while still remaining fair to concurrent flows on congested links. Unlike existing approaches which adapt classic TCP to a multi-homed CMT protocol, our approach does not depend on specific characteristics of TCP. Instead, we base on already entrenched functional blocks of CMT transfer, on the example of the CMT-enabled SCTP (Stream Control Transmission Protocol). In a simulative proof-of-concept analysis, we show that our approach - while relatively simple - is already quite effective.