. network, about 40% for the German one, and about 29% for the Italian one. In order to make a meaningful comparison, we will normalize the geographical dimen- sion of the network SO that all the considered networks will have an average link length equal to the German one. Considering Cm, the Italian and the German networks are quite meshed, having Cm = 27 and Cm > 30, respectively. In Figure 3.60, the normalized network costs are reported for the three normalized net- works with normalized traffic equal to 4 and in the presence of a mesh physical layer. It is evident that a topology dependence exists but it is not SO important to cancel the general validity of the results. A similar conclusion can be derived from Figure 3.61, where the network cost is evalu- ated versus Cm for an IP over next generation SONET architecture with a multiring and a mesh physical layers. The results are relative to a set of randomly generated networks with 12 nodes and the same average link length; circles refer to the ring topology, square to the Networks Fundamentals and Present Architectures Normalized CAPEX United States Germany Italy MPLS/DWDM Sonet/DWDM MPLS/OTN FIGURE 3.60 Normalized network cost for United States, Italian, and German normalized networks; normalized traffic equal to 4; mesh physical layer. Normalized cost (%) Rings Normalized average connection degree (Cm) FIGURE 3.61 Normalized network cost versus Cm for an IP over next generation SONET with a multiring and mesh physical layers. Random networks: 12 nodes and the same average link length, circles refers to the ring topology, squares to the mesh one; normalized traffic equal to 3 (average 12 channels at 10 Gbit/s for DWDM link). mesh one, and the normalized traffic is 3 (low traffic region, justifying the convenience of the ring topology at the physical layer). References 1. Building Industry Consulting Service International (BICSI), Telecommunications Cabling Installation, 2nd edn., McGraw-Hill Professional, New York, s.l., 2002, ISBN-13: 978-0071409797. Telec