Structured Stream Transport

Introduction

SST is an experimental transport protocol designed to address the needs of modern applications that need to juggle many asynchronous communication activities in parallel, such as downloading different parts of a web page simultaneously and playing multiple audio and video streams at once.

Features of SST:

Multiplexes many application streams onto one network connection
Gives streams hereditary structure: applications can spawn lightweight streams from existing ones
- Efficient: no 3-way handshake on startup or TIME-WAIT on close
- Supports request/response transactions without serializing onto one stream
- General out-of-band signaling: control requests already in progress
Both reliable and best-effort delivery in a semantically unified model
- supports messages/datagrams of any size: no need to limit size of video frames, RPC responses, etc.
Dynamic prioritization of application's streams
- e.g., load visible parts of a web page first, change priorities when user scrolls
Optional end-to-end cryptographic security comparable to SSL
Peer-to-peer communication across NATs via hole punching
Implemented as a library that can be linked directly into applications like SSL for easy deployment

Documentation

Research paper (PDF/PS/HTML, 12 pages), to appear in SIGCOMM 2007. Describes SST's principles and the most important design details.
Preliminary protocol specification (PDF, 22 pages). Provides a more thorough technical description of the protocol. Warning: Still incomplete and not entirely consistent with the current code or the SIGCOMM paper.
Preliminary SST library API documentation (HTML). Usable and hopefully moderately stable but still likely to evolve in non-backwards-compatible ways before the first "release".

Mailing List

The following public mailing list is available for discussions related to SST:

The SST Mailing List

Download

Warning: the code is still in a very early experimental state. Some features are broken or not completely implemented. Don't expect to be able to use it right away in a production system.

The SST library distribution does not yet have a stable release. Anonymous Subversion access is available however. You can browse the source code, or check out a copy of the repository:

  % svn co svn://svn.pdos.csail.mit.edu/uia/trunk/uia/sst

To build the library, make sure you have Qt 4.1 or later and OpenSSL 0.9.8 or later installed, then type:

  % cd sst
  % misc/setup
  % ./configure
  % make

To get started using the library in your application, see the main page of the API documentation.

Support

SST is a part of the UIA project at the Parallel and Distributed Operating Systems Group in MIT's Computer Science and Artificial Intelligence Laboratory. UIA is sponsored by the T-Party Project, a joint research program between MIT and Quanta Computer Inc., Taiwan, by the National Science Foundation under Cooperative Agreement ANI-0225660 (Project IRIS) and the NSF FIND program, with additional support from Nokia Research Center Cambridge.

Last Updated: $Id: index.html 1818 2007-03-28 14:18:44Z baford $