On token protocols for high-speed multiple-ring networks

A token ring protocol which restricts the transmission rights to the station possessing the token is not a good candidate for driving a gigabit network. As the network´s transmission rate becomes higher, the impact of the token transition time (which is idle) becomes more pronounced and the effective throughput of the network becomes a smaller and smaller fraction of the nominal channel capacity. The authors present a family of token passing protocols for ring networks which are devoid of this unpleasant property. The protocols are simple and inexpensive, yet they possess a number of advantageous properties: high capacity (similar to METARING and independent of the propagation length of the ring), fairness, and natural accommodation of synchronous and isochronous traffic