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 network design device includes: a division section for dividing a network having a plurality of channels and branch nodes into a plurality of linear partial networks using a predetermined terminating node or each branch node as the terminating nodes by allocating a device terminating one or more channels to be used to the terminating node and each branch node; an allocation unit for allocating a linear relay device and/or a reproduction relay device to a node constituting each partial networks to which a device has been allocated by the allocation unit; and a deletion unit for deleting a device terminating the channel allocated to the branch node for each path formed by the path formation unit according to the signal performance.

Abstract: A communications network system, which is comprised of a management network, a control network, and a user transmission network, includes signaling-based communication apparatuses, each consisting of a control node and a communication node, and non-signaling-based communication apparatuses without having associated control nodes. In this system, a path can be established in a user data transmission network by controlling a signaling process on the control network. The configuration of the communication node of the non-signaling-based communication apparatus is changed by a network management system provided in the management network, while the configuration of the communication nodes of the signaling-based communication apparatus are changed by the associated control nodes by successively transmitting a signaling message to the next control node on the control network.

Abstract: An optical transmission system that offers more efficient bandwidth usage in normal operation, as well as enhanced fault tolerance for higher service availability. A transponder converts high-priority and low-priority client signals into high-priority and low-priority wavelength signals to be added to network traffic. An optical switch fabric normally delivers high-priority and low-priority wavelength signals to high-priority and low-priority paths, respectively, where the two paths run in opposite directions. Such signals and paths are prioritized in terms of survivability against network failure. In case of a network failure, the optical switch fabric performs protection switching in either duplicate switching mode or path switchover mode depending on network failure information and drop wavelengths of each optical transmission device. In duplicate switching mode, high-priority wavelength signals are directed to both the high-priority and low-priority paths.

Abstract: To make reliable settings about pass monitoring in a short time. I/F parts are connected to other switching apparatuses or terminal units and receive or transmit a signaling message and a packet from or to these other switching apparatuses or terminal units. A route setting part refers to the source address and the destination address of a packet included in a signaling message to determine a path on which the packet will be transferred. A path monitoring control part refers to path monitoring information included in the signaling message as well as a monitoring method memory part and a belonging area memory part in order to make settings about monitoring of the path. The monitoring method memory part stores path monitoring methods to be adopted in the I/F parts. The belonging area memory part stores areas to which the I/F parts belong on a network.

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: 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: 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.

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 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: To provide a device and a method enabling a user to judge which route a path used at the present traces without being aware of whether the now-in-use path is a working path or a recovery path. A relay device positioned at a diverging node between the working path and the recovery path, when forwarding a message (e.g., a Path message and a Resv message each containing RRO) used for route trace, judges which type of path the path employed for forwarding the data at the present is coincident with and forwards the data to the relay device disposed on the in-use path, thereby actualizing the trace of the route used for forwarding the data at the present.

Abstract: An optical transmission system that offers more efficient bandwidth usage in normal operation, as well as enhanced fault tolerance for higher service availability. A transponder converts high-priority and low-priority client signals into high-priority and low-priority wavelength signals to be added to network traffic. An optical switch fabric normally delivers high-priority and low-priority wavelength signals to high-priority and low-priority paths, respectively, where the two paths run in opposite directions. Such signals and paths are prioritized in terms of survivability against network failure. In case of a network failure, the optical switch fabric performs protection switching in either duplicate switching mode or path switchover mode depending on network failure information and drop wavelengths of each optical transmission device. In duplicate switching mode, high-priority wavelength signals are directed to both the high-priority and low-priority paths.

Abstract: A network design device includes: a division section for dividing a network having a plurality of channels and branch nodes into a plurality of linear partial networks using a predetermined terminating node or each branch node as the terminating nodes by allocating a device terminating one or more channels to be used to the terminating node and each branch node; an allocation unit for allocating a linear relay device and/or a reproduction relay device to a node constituting each partial networks to which a device has been allocated by the allocation unit; and a deletion unit for deleting a device terminating the channel allocated to the branch node for each path formed by the path formation unit according to the signal performance.

Abstract: A spanning tree creation unit creates a plurality of spanning trees based on the network topology, and registers the spanning trees to a spanning tree information table. A spanning tree selection unit selects a spanning tree wherein communication resources will be used most effectively, out of the plurality of spanning trees registered to the spanning tree information table. A node setup unit sets the mapping information which expresses correspondence between the requested virtual LAN and the selected spanning tree in each node.