SDL specification and verification of a distributed access generic optical network interface for SMDS networks

This paper presents the design and specification of a BISDN user-to-network interface (UNI) named DRAGON (Distributed Access Generic Optical Network) for SMDS networks. The UNI allows clusters of nodes to be connected to an SMDS network via fiber-optic lines. The capacity of each line is shared by all the nodes in the cluster to make more efficient use of bandwidth. We constructed an extended finite state model (EFSM) of the DRAGON using ITU standard Specification and Description Language (SDL). The model was simulated and validated using the SDT 3.02 toolset from Telelogic. An extensive set of simulations were conducted to ascertain correct logical behavior. The model was then independently verified using two different algorithms: bit-state and random walk. The results showed that the design was verified to a high degree of coverage