Optical switch controller for fair and effective lightpath reservation in an optical network

摘要

An optical switch controller ("OSC") and method for use in a Generalized Multi-Protocol Label Switching ("GMPLS") network is described. A Used Pool ("UP"), an Available Pool ("AP"), and a Flagged Pool ("FP") are maintained at the OSC. The FP includes wavelengths that have been suggested but not yet reserved by a lightpath. The UP includes wavelengths that are currently being used by LSPs. The AP includes wavelengths not included in the UP or the FP. Each wavelength included in the FP includes a time stamp. At each node along the path during lightpath establishment, for each wavelength of the Label Set, if the wavelength is an element of the node's UP, the wavelength is extracted from the Label Set. If the wavelength is an element of the node's FP, a determination is made whether the local clock time minus the time stamp for the wavelength is less than a first threshold. If so, the wavelength is extracted from the Label Set; otherwise, the wavelength is extracted from the Label Set and included in a Flagged Set. For each wavelength of the FP, upon expiration of the time stamp, the wavelength is returned to the AP.