ADAPTIVE BANDWIDTH WASTE RATE - A FAIR BANDWIDTH SHARING SCHEME FOR THE DQ PROTOCOL WITH MULTIPLE PRIORITY CLASSES

In distributed queue dual bus (DQDB) networks, the distributed queuein g (DQ) protocol is used to control access of asynchronous data to the bus. This paper proposes a new scheme, the adaptive bandwidth waste ra te (ABWR) scheme, for fair bandwidth sharing among active nodes under the DQ protocol with multiple priority classes. With ABWR, each node a djusts the bandwidth waste rate for priority level j dynamically, depe nding upon the bus-wide bandwidth demand of a priority higher than j. We calculate the system capacity under the DQ protocol with ABWR. Four types of implementation are suggested, and their performance is evalu ated by simulation. With the proposed scheme, fair bandwidth sharing a mong active nodes is accomplished, wasting only a small portion of the bus bandwidth.