On Available Bandwidth in FDDI-Based Reconfigurable Networks

Networks used in mission-critical applications must be highly fault-tolemnt. W e propose an FDDI-Based Reconfigumble Network (FBRN) that can survive multiple faults. A n FBRN consists of multiple FDDI trunk rings and has the ability to reconfigure itself in the face of extensive damage. W e consider three classes of FBRNs depending on their degree of reconfigumbility: N-FBRN (nonreconfigumble), P-FBRN (partially reconfigumble) and FFBRN (fully reconfigumble). W e analyze the performance of FBRNs in terms of their available bandwidth in the presence of faults. In mission-critical systems, it is not enough to ensure that the network is connected in spite of faults; the trafic carrying capacity of the network must be sufficient to guarantee the required quality of service. W e present a probabilistic analysis of the available bandwidth of FBRNs given the number of faults. W e find that a fully reconfigurable FBRN can provide a high available bandwidth even in the presence of a large number of faults. A partially reconfigumble FBRN is found to be an excellent compromise between high reliability and ease of implementation.