This paper describes yet another variant on the distributed queue dual bus (DQDB) protocol. The fair distributed queue (FDQ) protocol is intended to be used on fiber optic metropolitan area networks similar to those used with DQDB. The authors claim that FDQ has better scalability than DQDB, with improved delay, throughput, and fairness characteristics over a wide range of distances, transmission rates, and numbers of nodes.

The improved performance claims for FDQ are based on simulation with the usual Poisson traffic assumptions. There is no discussion of the impact of different assumptions, such as self-similar traffic. Given the limited impact of DQDB-based standards in the marketplace for campus-wide networks compared with competitors such as fiber distributed data interface (FDDI), gigabit Ethernet, and asynchronous transfer mode (ATM), it seems that DQDB’s window of opportunity has passed. Consequently, this paper is recommended only to those with an academic interest in media-access protocols.