PROTECTION METHOD IN WAVELENGTH DIVISION MULTIPLEXING NETWORK

摘要

PURPOSE: A protection method in a wavelength division multiplexing network is provided to efficiently use network resources by making a rapid restoration in case that a fault occurs in a wavelength division multiplexing network. CONSTITUTION: A program judges whether the searching of an upload link to a destination node is required(S501). In case that the searching of the upload link to the destination node is required, the program searches for the shortest path(S502). At this moment, the program makes the wavelength(lambda) from a departure node to a fault upload link reused(S503). Then the program finds out all the shortest new paths from the upload link to the destination node(S504). The program judges whether the wavelength(lambda) of a link is being used(S505). If the wavelength(lambda) of a link is being used, the program recognizes the link having the wavelength(lambda) being used as a new fault link and judges whether the new fault link is identical to the fault link in a WP(Working Path)(S507). If the new fault link is identical to the fault link in the WP, the same wavelength(lambda) is defined(S508). If different, a new wavelength(lambda) is defined(S509).