Availability issues in the design of self-healing networks

A powerful approach to evaluating design options for fault-tolerant networks, such as modem transmission networks, from the point of view of availability is presented. A network for which demands are fixed in time and are routed through the network is considered. In the event of equipment failures, the demands can be rerouted. A fixed-point analytic method of modeling the availability of demands, to compare network topologies and routing schemes, to identify points of weakness, and to target investment in protection capacity, is applied. A method of estimating the variability of the out-turn end-to-end availability is also presented