lassical example is constituted by the CAPEX related to the routing of a new wavelength on a certain link. This is generally constant, but when the routing of the wave- length implies the deployment of a new DWDM system, then it becomes very high SO limiting as much as possible the opening of new DWDM systems. Another typical application of dynamic constrains is possible when the number of fibers connecting the network nodes are not unlimited, for example, since the carrier is leasing them, and the bare use of a fiber has its own cost. In this case the cost of using a link for a new wavelength depends on the link length, on the number of fibers available along the link and on the leasing price if applicable. In this condition a dynamic link cost tag is very effective in performing a correct network optimization. The design methods based on routing strategies are only one of the classes of heuristic algorithms that has been devised to design GMPLS networks. A more complete analysis can be done starting from the following biographies [22-24]. 8.4.3.3 Comparison among the Considered Algorithms In comparing the different heuristics we have introduced, we will take as a reference the results obtained using the ILP optimization. The comparison is based on sets of 10 random networks designed to cover an approxi- mately square area of the dimension of Italy for all the considered values of the number of nodes. All the considered networks have a connectivity (average number of disjoined path between couples of nodes) around 2.2 and the design does not include any survivability mechanism. The traffic matrix is uniform and composed of three GLSPs between each couple of OXC. When the order of the connection request is required the dimensioning is repeated in 10 ran- dom orders and the lower cost is accepted. The comparison result is reported in Figure 8.26. All costs are normalized with respect to the optimized cost obtained with the ILP. The first observation is that there is a good performance of the routing-based algo- ri