Verifying Large SDL-Specifications Using Model Checking
SDL '01 Proceedings of the 10th International SDL Forum Copenhagen on Meeting UML
A framework for verifying data-centric protocols
FMOODS'11/FORTE'11 Proceedings of the joint 13th IFIP WG 6.1 and 30th IFIP WG 6.1 international conference on Formal techniques for distributed systems
| Hi-index | 0.00 |
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. Within each cluster, transmissions are scheduled on first-come-first-served (FCFS) order of message arrivals, by considering a globally distributed queue. A novel scheme is proposed for controlling access to the fiber-optic transmission network. By using two logically separate subnetworks called the reservation channel and the reservation ring Slot reservations and message transmissions can proceed independently and concurrently. The reservation channel is a broadcast channel for notifying nodes within the cluster when to reserve a slot. Access to the reservation channel is controlled by the reservation ring: a token ring network. All accesses for the queue slots are completely fair and the bandwidth attainable is independent of the position of the node within the cluster. Unlike previous distributed queue protocols, the DRAGON facilitates both fixed-sized and variable sized transmissions. 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.O2 toolset from Telelogic. An extensive set of simulations were conducted to acertain 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.