Abstract: A relay node used in a WDM optical network is disclosed. The relay node includes: a high-speed side port configured to send and receive a high-speed signal; a low-speed side port configured to send and receive a low-speed signal; a unit configured to generates a checking message for requesting another node to report constraint information of a low-speed side port of the another node, wherein the constraint information relates to adding an optical signal from the low-speed side port to a high-speed side port of the another node or dropping an optical signal from the high-speed side port to the low-speed side port of the another node; a unit configured to generate a response message including the constraint information of the own node in response to receiving the checking message sent from the another node; and a storing unit configured to store at least the constraint information of the another node.

Abstract: The present invention relates to a communication path calculation method and module. More particularly, the present invention provides a communication path calculation method and module that are implemented or incorporated in a transmission apparatus including a ROADM or the like which performs WDM communication, advertises information on a wavelength which can be added or dropped, as information on a link, and uses the information to autonomously calculate a communication path. Optical transmission equipment that is accommodated in a WDM network over which a wavelength-division multiplexed signal is transferred includes a reconfigurable OADM module. For calculation of a communication path, the OADM module creates a link table listing clients of the own equipment and connected WDMs, and advertises the link table to the other pieces of equipment accommodated by the network as pieces of information on restrictions to be imposed on routing from the own equipment.

Abstract: A path routing computation method enables reduction of the memory capacity for path routing computation. The method is characterized in that a wavelength convertible subnetwork in which paths are connected in a mesh form; a first and second wavelength inconvertible subnetworks have a starting point node and an end point node, respectively, and include a plurality of nodes and connected via the wavelength convertible subnetwork, and out of the nodes constituting the first and second wavelength inconvertible subnetworks, a node has a port connected to the wavelength convertible subnetwork is defined as a border node, and the method includes the steps of: obtaining, for the first wavelength inconvertible subnetwork, a path from the starting point node to a border node in the first subnetwork; and obtaining, for the second wavelength inconvertible subnetwork, a path from the end point node to a border node in the second wavelength inconvertible subnetwork.

Abstract: In a network having a main route and a protection route, a branch node reflects label limit information for the main route into the label limit information for the protection route, and allocates to the main route, a label related to the label for the protection route. On the other hand, a merge node reflects label limit information for the protection route into the label limit information for the main route, and allocates to the protection route, a label related to the label for the main route. Thus, labels having a relation can be allocated to the main route and the protection route.

Abstract: A relay node used in a WDM optical network is disclosed. The relay node includes: a high-speed side port configured to send and receive a high-speed signal; a low-speed side port configured to send and receive a low-speed signal; a unit configured to generates a checking message for requesting another node to report constraint information of a low-speed side port of the another node, wherein the constraint information relates to adding an optical signal from the low-speed side port to a high-speed side port of the another node or dropping an optical signal from the high-speed side port to the low-speed side port of the another node; a unit configured to generate a response message including the constraint information of the own node in response to receiving the checking message sent from the another node; and a storing unit configured to store at least the constraint information of the another node.

Abstract: The present invention relates to a communication path calculation method and module. More particularly, the present invention provides a communication path calculation method and module that are implemented or incorporated in a transmission apparatus including a ROADM or the like which performs WDM communication, advertises information on a wavelength which can be added or dropped, as information on a link, and uses the information to autonomously calculate a communication path. Optical transmission equipment that is accommodated in a WDM network over which a wavelength-division multiplexed signal is transferred includes a reconfigurable OADM module. For calculation of a communication path, the OADM module creates a link table listing clients of the own equipment and connected WDMs, and advertises the link table to the other pieces of equipment accommodated by the network as pieces of information on restrictions to be imposed on routing from the own equipment.

Abstract: A path routing computation method enables reduction of the memory capacity for path routing computation. The method is characterized in that a wavelength convertible subnetwork in which paths are connected in a mesh form; a first and second wavelength inconvertible subnetworks have a starting point node and an end point node, respectively, and include a plurality of nodes and connected via the wavelength convertible subnetwork, and out of the nodes constituting the first and second wavelength inconvertible subnetworks, a node has a port connected to the wavelength convertible subnetwork is defined as a border node, and the method includes the steps of: obtaining, for the first wavelength inconvertible subnetwork, a path from the starting point node to a border node in the first subnetwork; and obtaining, for the second wavelength inconvertible subnetwork, a path from the end point node to a border node in the second wavelength inconvertible subnetwork.

Abstract: In a network having a main route and a protection route, a branch node reflects label limit information for the main route into the label limit information for the protection route, and allocates to the main route, a label related to the label for the protection route. On the other hand, a merge node reflects label limit information for the protection route into the label limit information for the main route, and allocates to the protection route, a label related to the label for the main route. Thus, labels having a relation can be allocated to the main route and the protection route.