Abstract: A network design method proceeds by generating cycles, evaluating the economics of building rings on those cycle, and building any economic rings. Generating a cycle involves picking two endpoints between which two disjoint link and node paths are desired—the two nodes selected are thus nodes on the candidate rings. Once a cycle is generated, various combinations of OADM/ADM nodes on the cycle are tried, from rings using three nodes to rings using all of the nodes on the cycle. The network design method considers a sequence of SONET/SDH and DWDM rings on each cycle generated, and compares the cost of carrying demand by SONET/SDH rings, DWDM rings, and an alternative dual-hub benchmark architecture. The ring constraints such as maximum circumference are applied before ring costs are calculated, and rings violating those constraints are eliminated from consideration.