Dynamic management of non-isochronous multipriority traffic in DQDB metropolitan area networks

Abstract

Digital networks have to interconnect remote computers in order to make available a communication link between them, assuring high transmission rates, effective error control systems and low blocking probabilities. In this paper, a dynamic management of DQDB Multiple Access Control is proposed. It is based on the opportune activation of the Increasing Counter Priority Controlled mechanism, driven by the traffic levels present at the user interfaces. The goal is to make the operation of the Metropolitan Area Networks clear and effective for multipriority interworking between remote computers. An analytical model, able to identify the correct activation threshold, as a function of the intensity and distribution of the load, is here reported and its results are compared with the outputs provided by a DQDB network simulator. The advantages obtainable with the considered policy, in terms of transmission rate and access delay, are shown and discussed.