ASN.1 and Estelle Implementation support tools

Formal specifications are a well-known technique for improving software development. In the context of OSI communication protocol standards, Formal Description Techniques (FDT's) have been developed for the description of communication protocols and services. In addition, a notation called ASN.1 is used for the descriptions of the data structures of protocol data units exchanges between communicating entities at the application layer. Existing FDT's, such as Estelle, LOTOS and SDL, do not include facilities to directly manipulate data structures defined in ASN.1. This makes using FDT's for distributed applications difficult. This paper deals with the integration of ASN.1 with Estelle and the issues involved with the integration of corresponding implementation tools. It is shown how the encoding and decoding routines automatically generated from the ASN.1 definitions can be combined with implementation code semi-automatically generated from the Estelle specification of the protocol. An ..