 practical networks it almost never happens that a node has no local traffic, we will assume that an LSR is always superimposed on an OXC at every node. Equipment type is already selected when doing network dimensioning at every network layer, thus all the cost parameters are given. In particular, the DWDM layer is composed only of one type of wavelength channel with a given capacity (let us say 10 Gbit/s). As far as QoS is concerned, we will simplify the situation with respect to a real- istic case and we will assume that all the GLSPs are on the same level as far as the survivability is concerned. Also in this case introducing high priority (that is, protected or restored) and best effort GLSPs simply complicate a bit the model, but does not introduce any new element. Introducing realistic QoS classes on the con- trary has quite an impact on the optimization model. Several studies have been done in this direction, see, for example, Refs. [13,14]. We will also assume that a maximum number of GLSPs requests can be done between the same couple of nodes. This is a reasonable limitation, aimed at limit- ing the number of ports of the network nodes. All the MPLS LSPs will have the same capacity (e.g. 1.2 Gbit/s) that is assumed the unit of capacity of the network. Also this condition can be removed with a slight modification of the optimization algorithm if it is needed. Convergent Network Management and Control Plane In principle, an ideal optimization should be carried out by contemporarily assign- ing both working and survivability resources. We will see that the ILP problem deriving from the multilayer optimization is very complex (precisely NP-hard). Thus, to simplify the solution under a computational point of view, we will design the network in two steps: first assigning the working resources and in a second phase the survivability ones. The decision of performing a two-step dimensioning, first working capacity and then protection or restoration, deserves some comments. Several studies in literature dem- onstr