The No Slot Wasting Bandwidth Balancing Mechanism for Dual Bus Architectures

A Bandwidth Balancing (BWB) mechanism has been recently added to the distributed queueing algorithm of DQDB. BWB can provide the requested throughputs by lightly loaded stations and evenly distribute the remaining channel bandwidth among overloaded stations. However, its operation requires the wastage of channel slots. In this paper, we introduce a new bandwidth balancing mechanism for DQDB. The operation of the new mechanism requires one additional bit in the Access Control Field (ACF) of the slot but has the advantage of exhibiting a similar behavior with the current BWB mechanism of DQDB without wasting any channel slots. For this reason, it can converge faster to the steady state where fair bandwidth allocation is achieved. We investigate the throughput and delay performance of the proposed mechanism under one traffic class and examine its capacity to support multiple priority classes of traffic. We also compare its performance with the corresponding performance of the BWB mechanism of DQDB.