FDDI - Introduction
FDDI is a token passing network with single or dual ring station interface implemented with fiber optics, shielded twisted pair, or unshielded twisted pair. The data rate is 100 Mb/s, default network parameters assume 1000 stations and 200 km circumference.
There are three basic types of station; single attach, dual attach, and dual attach concentrator.
A dual ring provides secondary backup in case of primary ring failure