Survivable SONET networks-design methodology

A prototype software system that implements a methodology for the strategic planning of survivable interoffice networks is presented. The software system determines strategic locations and ring types for Synchronous Optical Network ring placement. Two types of survivable network architectures are considered-1 : 1 diverse protection and SONET self-healing rings. The software considers three types of SONET self-healing rings-unidirectional, 2-fiber bidirectional, and 4-fiber bidirectional. Hubbing is assumed in all architectures. Inputs include nodes, links, connectivity, facility hierarchy, and multiyear pointto-point demands, together with the costs of fiber material and splicing, route mileage (installation), and multiplexors and regenerators of different rates. The outputs are a set of near-optimal rings based on cost, specifying the ring types and rates, fiber span sizes and counts, regenerator locations and speeds, the topology (set of links to be used), and the network cost. In addition, the software outputs the time in the planning period that each ring and fiber span should be installed.