On SCTP multi-homing performance

The Stream Control Transmission Protocol (SCTP) is a general purpose transport protocol featuring multi-homing support, message oriented and more flexible data delivery mechanisms than TCP, and an increased protection against well-known attacks. Originally developed for the transport of Signaling System No. 7 messages, e.g. MTP level 3 user primitives, over IP networks, SCTP has evolved to a general purpose transport protocol with a wide field of applications. With respect to multi-homing, the current SCTP standard uses this feature for network level redundancy only. Therefore we propose and evaluate in this contribution mechanisms for the application-specific optimisation of the SCTP protocol behaviour with respect to its multi-homing capabilities. To satisfy the extremely strict performance requirements for signalling transport, efficient load sharing among all active links is also highly desirable in SCTP scenarios. To this end, we propose a novel, improved load sharing algorithm for SCTP with path based selective acknowledgements which avoids some of the drawbacks of the existing algorithms and achieves an increase in throughput. Results of a comparative simulation study are presented to demonstrate the benefits of our algorithm.