FairQDB: a new simple and optimal access mechanism for dual bus networks

The authors present a new access control scheme for dual bus networks which is absolutely fair in bandwidth sharing and can replace the DQDB access protocol without changes in the transmission system apart from the protocol machine. The mechanism retains all the positive features of DQDB including simplicity, robustness, flexibility, 100% bandwidth utilization and zero access delay at very low load. In addition, it can be set to provide a bandwidth sharing pattern that is different from a uniform one, as may be the case if bridges or other large users are present, and priorities can be easily superimposed.<>