On the design of performance-constrained survivable networks

The authors describe a network design algorithm that combines standard traffic flow analysis with previously ignored topological survivability considerations. The proposed approach uses a version of the cut-saturation algorithm modified to include considerations for survivability in the process of adding and deleting link resources to meet specified throughput goals. This approach improves on the original design process, which made decisions on which link should be added or deleted solely on the basis of link use and link cost. Link distance was used for link cost when all links had the same capacity. Survivability considerations were directly introduced into the design process by using the information provided by the ND (node decomposition) and LT (link tree) indexes to indicate which links to add or delete. Considerations of the LT and ND indexes, along with link use and link cost (i.e., distance), result in network designs that meet performance requirements, tend to minimize total link distance, and are survivable.