ENHANCEMENTS OF DQDB PROTOCOL WITH ECBWB MECHANISM FOR FAIR ACCESS AND MULTI-PRIORITY TRAFFIC MANAGEMENT

The Distributed Queue Dual Bus (DQDB) protocol with BandWidth Balancin g (BWB) mechanism is unable to effectively support multiple priority l evels that may be necessary for providing new services to network user s. Thus. fair allocation of bandwidth among users is assured only in t he case of one level of traffic priority. To overcome this limitation, this paper introduces a novel mechanism called Extended Counting Band Width Balancing (ECBWB), which augments and enhances the operation of the current BWB mechanism. Simulation results, obtained under particul arly severe traffic overload conditions, show that the proposed mechan ism has better performance but minimal added complexity with respect t o the current version of the protocol.