A distributed access generic optical network interface for SMDS networks

This paper presents the design and analysis of a BISDN user-to-network interface (UNI) for SMDS networks. The UNI allows clusters of nodes to be connected to an SMDS switching network via fiber-optic lines. The capacity of the line is shared by all the nodes in the cluster, thus making more efficient use of its 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 separate subnetworks called the reservation channel and the reservation ring. Slot reservations are made independently from the message transmissions. VHDL was used to construct an RTL model of the UNI. Accurate timing simulations were performed on a cluster of three nodes, and the model was validated using concurrent video and data traffic. Clusters of different sizes were modelled and simulated. Using integrated VBR video and Ethernet traffic traces from Bellcore, a number of quality-of-service (QOS) parameters were measured and are presented.