A lightpath segmentation system and method for use in a GMPLS network is described. In one embodiment, lightpaths are divided into segments according to the distribution of the wavelength-converter-equipped optical switches, or nodes, within a WDM network. As the number of hops within the segment increases, a lightpath segmentation probability increases. When a wavelength-converter-equipped node receives an LSP Request message, it calculates the LPSP and, if the LPSP exceeds a threshold, the node sets up a lightpath between itself and the ingress node or a previous upstream wavelength-converter-equipped node, if the lightpath has already been segmented.