1. A method for DWDM network planning, the method comprising: determining a highest aggregate demand from among a set of demands associated with a region of interest; determining a total number of lightpaths at discrete line granularities beginning with the highest aggregate demand; determining a DWDM network topology comprised of a plurality of nodes and one or more wavelengths extending between the nodes based on the total number of lightpaths at discrete line granularities; routing lightpaths along the wavelengths extending between the plurality of nodes based at least on predetermined decision criteria; routing demands onto tributaries extending along the lightpaths based at least on predetermined guidelines; determining node-related hardware parameters based at least on a predetermined routine; calculating a cost associated with the node-related hardware parameters; and outputting the node-related hardware parameters and the associated cost.