Beneficial Transparent Deployment of SCTP: The Missing Pieces

The Internet-wide deployment of new transport protocols such as the Stream Control Transmission Protocol (SCTP) is a difficult matter. While SCTP could be beneficial in many cases, it is still a major challenge to enable applications to use the new protocol. We believe that its deployment could be significantly accelerated by introducing an intermediate step: transparent usage below TCP, such that TCP-based applications automatically obtain a benefit. We have implemented a Linux based TCP-SCTP mapping tool that exploits SCTP's multi-streaming feature, and carried out measurements which show that such an approach can significantly improve the performance of TCP applications. However, and perhaps more importantly, we also encountered difficulties, which lead us to make some concrete recommendations regarding future research and the implementation and specification of SCTP itself.