On the specification and implementation of X.25 using CSP and OCCAM

Abstract The need for formal specification of data communications protocols plays an important role in modern protocol development. The use of parallel-processing technology promises significant performance gains in support of modern bandwidth-intensive applications. The paper concerns the implementation of a formally specified data communications protocol. The paper describes the CSP specification and occam implementation of the X.25 LAPB (ISO layer two) protocol. The development process, the software architecture, and the parallel computing environment are presented in the paper.