Abstract: A node for configuring a ring type network system in such a mode that a plurality of physical links belonging to difference rings exists between nodes opposite to each other, has a storage unit stored with link associated information representing an associated relationship between ports of physical links and a port of a virtual link virtually set up to at least one physical link, ring configuration information representing a paired relationship of the ports of the physical links configuring the different ring, port numbers of both ends of the physical link and port numbers of both ends of the virtual link, and a processing unit executing a process of transmitting, to other nodes, such information that one virtual link is associated with the plurality of physical links belonging to the different ring, and setting up, when receiving a signaling message for setting up a path, the path passing through the same ring on the basis of pass route information in the message and the storage information stored in the sto

Abstract: A node apparatus in a ring network in which a protection path is provided that cycles around the ring network and transports a signal in a direction opposite to a signal transporting direction of the working path and in the event of a failure of the working path, a node apparatus adjacent to the failure loops back the signal flowing on the working path onto the protection path, the node apparatus comprising: allowable bandwidth storing unit which stores a maximum total bandwidth value, which represents the largest value among per-link total values of bandwidths that a plurality of working paths use on respective links connecting between the node apparatuses, as an allowable bandwidth for a shared path; and bandwidth control unit which controls the bandwidth of traffic flowing on the protection path, in accordance with the allowable bandwidth.

Abstract: A communication apparatus stores therein link information indicating a network connection status of an entire hierarchical network, collects link information indicating a network connection status in its own area in predetermined cycles, and transmits the collected link information to another area assigned a level different from a level assigned to its own area. When receiving link information from another area assigned a different level, the communication apparatus determines whether the received link information is new link information newer than link information stored in a predetermined storage unit; when it is determined that the received link information is new link-information, the communication apparatus stores the new link information into the predetermined storage unit and advertises it in its own area; by contrast, when it is determined that the received link information is not new link-information, the communication apparatus discards the received link information without storing and advertising.

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: A transmission device, which carries out a route control of a frame based on a label included in the frame in a ring network, includes: a generating unit that generates a message for collecting information on first/second labels allocatable to working/standby routes; a transmitting unit that transmits the message in the ring network; a receiving unit that receives the message after being circulated in the ring network; and a selecting unit that selects one of the first/second labels for the working/standby route based on the information included in the message.

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: A signaling apparatus is applied to a node constituting a network including internal network to network interface (INNI) domains having INNI interfaces between a plurality of networks in an area and external network to network interface (ENNI) domains having ENNI interfaces that connect the INNI domains. The apparatus includes a processing unit that processes a signaling message for setting a path when an end-to-end path that passes through the INNI domains and the ENNI domains that connect the INNI domains is set in response to the signaling message, a storing unit that holds information on types of links between an own node and adjacent nodes, and a judging unit that judges whether the own node is a connection end point of the INNI domains or the ENNI domains with reference to route information in the message and the information on the types of the links held in the storing unit.

Abstract: A relay node comprising a reception station for receiving a route trace control message including routing information on a path used for data transfer from a starting node to a terminal node from the preceding node on the path, an editing section for, if the home node is boundary node located at the boundary of a routing information shielding section on the path, editing so that a portion on the routing information shielding section of the routing information included in the route trace control message received by the reception section cannot be identified, and a transmission section for sending out a route trace control message after the edition to the node of the subsequent stage, which is located on the path.

Abstract: A signaling system able to improve the efficiency of utilization of network resources and autonomously set a correct spare route, that is, a signaling system setting a path passing through two rings interconnected by a plurality of nodes by signaling wherein each node is provided with an inter-node connection information table including topology information in the network and a branch node judgment unit for judging whether a home node is a branch node based on the content of the inter-node connection information table and wherein when the home node receives a signaling message for setting a working path and it is judged that the node is a branch node, the signaling of the spare path is started for the destination node of the spare path based on the information in the inter-node connection information table so as to autonomous set the spare path.

Abstract: A node in a first ring stores therein connection information about connecting nodes between a second ring and a third ring. Upon receiving a route of a working path by a signaling, the node determines any one of nodes composing the second ring as a branch node. If the working path is not terminated on an end node that the working path ends in the second ring thereon, and also if no node composing the second ring stores therein connection information between the end node and any one of the connecting nodes in the third ring that is connected to the second ring, the node compares each condition of selectable routes of a backup path between the end node and the branch node, and selects any one of the selectable routes as the backup path based on a result of comparison.

Abstract: A transmitting apparatus in a network constituted of a plurality of rings connected via a plurality of routes includes a node type determining unit and a backup path setting message transmitting unit. The node type determining unit determines, on receipt of a working path setting message requesting to set a working path, whether the transmitting apparatus is any one of a branch node at which a backup path is branched off from the working path or a merge node at which the backup path merges into the working path. The backup path setting message transmitting unit transmits, when the transmitting apparatus is determined to be a branch node or a merge node, a backup path setting message specifying a route from a ring including the transmitting apparatus to a connection node connecting the ring and a neighboring ring.

Abstract: When opposed communication transmitting apparatuses A and C are connected in a physical configuration thorough a communication transmitting apparatus B, if an interface configuration changing command is input to the communication transmitting apparatus B, the interface configuration is changed in the communication transmitting apparatus B and virtual connection is achieved such that the opposed communication transmitting apparatuses A and C pass through the communication transmitting apparatus B to directly connect an interface A1 and an interface C1. In this situation, since the GMPLS operation target apparatuses are only the communication transmitting apparatus A and the communication transmitting apparatus C and the communication transmitting apparatus B is a non-target apparatus of the GMPLS operation, the GMPLS scalability problem is solved and optical signals may be transferred at higher speed.

Abstract: A node in a first ring stores therein connection information about connecting nodes between a second ring and a third ring. Upon receiving a route of a working path by a signaling, the node determines any one of nodes composing the second ring as a branch node. If the working path is not terminated on an end node that the working path ends in the second ring thereon, and also if no node composing the second ring stores therein connection information between the end node and any one of the connecting nodes in the third ring that is connected to the second ring, the node compares each condition of selectable routes of a backup path between the end node and the branch node, and selects any one of the selectable routes as the backup path based on a result of comparison.

Abstract: A ROADM device generates link information including a virtual link in which a first link that is used by a node apparatus for transmitting a signal and a second link of a ROADM device that is capable of branching a signal transmitted via the first link when the signal is transmitted via a WDM network are virtually connected each other, and transmits the generated link information.

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: A protecting route design method is disclosed for a communication network including a plurality of nodes having preset information on a protecting route to switch over in parallel from a working route thereto when link or node failure occurs, according to a failure notification message including failure location information being transmitted from a failure detection node to each node. The protecting route design method includes the steps of searching a protecting route which can minimize a transfer time of the failure notification message from the failure detection node; and then, updating the searched protecting route to a protecting route having a spare communication capacity sharable for a different failure and having a route switchover time to be completed within a given time limit.

Abstract: A signaling system able to improve the efficiency of utilization of network resources and autonomously set a correct spare route, that is, a signaling system setting a path passing through two rings interconnected by a plurality of nodes by signaling wherein each node is provided with an inter-node connection information table including topology information in the network and a branch node judgment unit for judging whether a home node is a branch node based on the content of the inter-node connection information table and wherein when the home node receives a signaling message for setting a working path and it is judged that the node is a branch node, the signaling of the spare path is started for the destination node of the spare path based on the information in the inter-node connection information table so as to autonomous set the spare path.