An interesting retrospective of a decade of transport protocol research with SCTP

TCP is still the dominant transport protocol on the Internet. However, since the late 1990s, researchers and IETFers have worked on developing and improving another reliable transport protocol for the Internet : SCTP. The Stream Control Transport Protocol (SCTP) RFC 4960 provides several additional features compared to the venerable TCP, including :

  • multihoming and failover support
  • partially reliable data transfer
  • preservation of message boundaries
  • support for multiple concurrent streams

The main motivation for the design of SCTP has been the support of IP Telephony signaling applications that required a reliable delivery with small delays and fast failover in case of failures. SCTP has evolved to support other types of applications.

Since the publication of the first RFC on SCTP, various research groups have proposed extensions and improvements to SCTP. SCTP’s flexibility and extensibility has enabled researchers to explore various new techniques and solutions to improve transport protocols. A recently published survey paper [1] analyses almost a decade of transport protocol research by looking at over 430 SCTP related publications. Like most survey papers, it provides an introduction to the paper topic, in this case SCTP and briefly compares some of the studied papers.

[1] goes beyond a simple summary of research papers and the approach chosen by the authors could probably be applicable in other fields. In order to understand the evolution of the main topics of SCTP research, the authors of [1] classified each paper along four different dimensions :

  • protocol features (handover, load sharing, congestion, partial reliability, ...)
  • application (signaling, multimedia, bulk transfer, web, ...)
  • network environment (wireless, satellite, best effort, ...)
  • study approach (analytical, simulation, emulation, live measurements, ...)

By using these four dimensions [1], provides a quick snapshot of the past SCTP research and its evolution over the years. Not surprisingly, simulation is more popular than live measurements or bulk data transfer is more often explored than signaling. Furthermore, [1] provides interesting visualization such as the figure below on the chosen study approach.

../../../_images/sctp.png

Fourth dimension : the study approach used for SCTP papers during the last decade [1]

[1] is a very interesting starting point for any researcher interested in transport protocol research. The taxonomy and the presentation could also inspire researchers in other fields. A web interface for the taxonomy is also available. Unfortunately, it does not seem to have been maintained after the finalization of the paper.

[1](1, 2, 3, 4, 5, 6, 7) \Lukasz Budzisz, Johan Garcia, Anna Brunstrom, and Ramon Ferrús. A taxonomy and survey of sctp research. ACM Comput. Surv., 44(4):18:1–18:36, September 2012. http://doi.acm.org/10.1145/2333112.2333113.