The performance of interconnected ring networks with priority

The performance of a hierarchical ring network in which a number of outer rings interconnected through an inner ring backbone network is studied. The connection between outer and inner rings is provided through gateways. The Poisson arrival of messages to the outer ring station is assumed, with two classes of messages. Class 1 is an interring message, while a class 2 message stays on the same ring. Class 1 messages are given nonpreemptive priority over class 2 messages. By means of a certain independence assumption and under a limited service discipline, outer ring stations are modeled as M/G/1 with priority. The gateways are modeled as G/G/1 queues. In both types of queues, a message initiating a busy period receives special service. The delays of class 1 and class 2 messages are derived. The numerical results derived from the analysis show excellent agreement with results obtained by simulation