Specification and analysis of the SNR high-speed transport protocol

Abstract

In recent years the emergence of optical fiber and its correspondingly high data rates have led to the development of much higher speed networks, both locally and over the long haul. These developments led to the design of new transport pro­tocols, which were intended to take advantage of the high-speed networks. A number of these so-called "high-speed transport protocols" have been designed to date. This paper considers one of these, called the SNR protocol, in detail. A formal specification of the protocol is presented, using the protocol model systems of communicating machines, and the protocol is then analyzed through the specification. An implementation of the protocol based on this formal definition has also been made, and used to simulate the protocol, providing further insights into its performance. Based on the combined results of the analysis and the simulated protocol, a high degree of confidence is gained in the correctness of the protocol. The specification is quite detailed, and from it an implementation should be fairly straightforward. The paper also discusses the difficulties encountered during the analysis of such a complex protocol, and suggests some possible solutions to these problems. Finally, as a result of this work, we comment on the strengths and weakness of the SNR protocol as a solution to the high-speed transport protocol problem, and make two simple suggestions for improving it.