Controlled request DQDB: achieving fairness and maximum throughput in the DQDB network

The author presents a new technique, called controlled request, to combat the unfairness problem in the distributed queue dual bus (DQDB) protocol that achieves 100% throughput. Transmission of requests in the controlled request DQDB method is controlled by a mechanism that is similar to the one used in DQDB to transmit segments. Fairness is achieved by using the bandwidth balancing technique to prevent an overloaded node form continuously transmitting requests. Simulation studies showed that the controlled request DQDB scheme achieves better performance than the DQDB protocol with bandwidth balancing