gorithm is lower with respect to an ILP opti- mization, both for very large networks (cyclic algorithms are not NP complete) and for a small number of nodes. The complexity of cyclic algorithms is strongly influenced by the traffic to be routed due to the necessity of cycling on the set of paths to be routed. In order to propose an example of the use of these algorithms, we will consider a pos- sible topology of the Italian core network whose topology we already used in Chapter 3 and that we will repeat here for reference in Figure 10.27. It is interesting to note that the test network has 32 nodes; thus, it would be very difficult to analyze it using an ILP algorithm, also if only working capacity is considered and the optical and MPLS layers are separately designed. We propose results for the working capacity dimensioning without considering the sec- ond step of the algorithm that allows completing the project by adding capacity to support the selected survivability method. Here, we are interested in analyzing what happens when the different strategies of plac- ing of WCs are applied. In Figure 10.28, the normalized cost for different designs of the optical transparent net- work on the Italian topology are compared: systems with 128 and 64 wavelengths are considered besides the three types of OXCs described in the previous section. Electronic regenerators are not allowed, that is a rational strategy due to the geographic area occupied by the network. The network cost is essentially composed of the following terms: DWDM platform (EDFAs, common parts, AWGs) DWDM transparent transponders (adapt the signal to the transmission with a fil- ter and control the power with a variable attenuator) Telecommunication Networks Bolzano Milano Trieste Verona Torino Venezia (mestre) Genova Bologna Firenze Ancona Perugia Pescara Napoli Potenza Cagliari Catanzaro Palermo Catania FIGURE 10.27 A possible topology of the Italian core network. No WCs 128 wavelengths 64 wavelengths all WCs FIGURE 10.28 Normalized cost for different de