nuity at the layers' boundary has to be set. Remembering that an LSR is always present where there is an OXC, we can say that the LSPs traversing the LSR (that is, passed from layer 1 to layer 2 in the nodes) will be in general a subset of the LSR traversing the OXC. This subset has to coincide with the set of LSPs carried by a certain number of wavelengths. Mathematically this condition is expressed as 1 (Vi,j,h,ke [1, [1,M]) (8.22) Moreover, the number of LSPs terminated in a node has to coincide with the correspond- ing entry of the traffic matrix, thus 2N 2N M (8.23) 1N 1 N M (8.24) Telecommunication Networks After the bidirectionality, it is needed to assure that the number of wavelengths deployed on each link is sufficient to support the traffic routed along that link and to assign the LSPs to the wavelengths SO that passing a set of LSPs between the layers at a certain node coincides with the termination of a certain number of wavelengths in that node. This con- straint requires to introduce the number of wavelengths terminated in a node and the number of wavelengths that bypass the node without termination. We will call [S] III {WO}}}} the Nx1N matrix containing the wavelength bypassing node k when arriving from link h-k. The requirement of a certain wavelength number is writ- ten as =1,...1N) (8.25) while the condition on the wavelength termination, utilizing the fact that the locally dropped LSPs are the same both on layer 1 and on layer 2, can be written as (8.26) and finally (8.27) where W is the maximum number of MPLS LSPs that can be multiplexed into a wavelength. After the constraints on bidirectionality and capacity, we have to impose the GLSPs con- tinuity through the network. This means two things: 1. If the routing matrix tells that a certain GLSPs travels at layer S from node h to node k with one hop, these nodes have to be contiguous in their own layer, which means that sank have to be equal to 1. 2. Successive hops have also to be contiguous, that is, the GLSP can go from node h to node k an