Virtual routers that abstract photonic sub-domains are provided for GMPLS networks. A virtual router uses a link viability matrix to keep track of the set of viable connections between inputs and outputs of a photonic sub-domain. A virtual router may receive RSVP-TE signaling messages and either allocate a working input to output link pair or, if explicitly signaled, verify that the requested link is currently viable. A virtual router also advertises, in its link state updates, the current set of possible outputs for any input link. Shortest path computations can be implemented utilizing virtual routers by modifying a topology graph in accordance with the link viability matrix of the virtual router.