An availability comparison of three concentrator alternatives in a fiber distributed data interface ring network

Several different alternatives are under consideration by the ANSI X3T9.5 committee for the implementation of a concentrator in a fiber distributed data interface (FDDI) ring. The alternatives differ in the number of MAC (medium access control) chips present in the concentrator. The three alternatives are compared by evaluating the availability of simple networks constructed with concentrators of each type. The analysis considers the variations in the failure rates introduced by the different alternatives as well as variations in other parameters such as repair times and coverage factors