Abstract: In a disclosed backup path bandwidth keeping method for keeping bandwidth of a backup path to which an active path is switched when the active path becomes unavailable in nodes of a communication network, each node is connected to the same destination, and the method includes a backup path bandwidth keeping phase, for M (M is a natural number equal to or less than L) channels in L (L is a natural number) channels kept as backup path bandwidth, for notifying a destination-side node existing in a destination side of the backup path of identification number information of the M channels to be kept and identification information indicating that a path for which the bandwidth is to be kept is a backup path.

Abstract: An ATM switch includes a first stage, a second stage and a third stage each of which stages includes at least one basic switch, wherein the first stage, the second stage and the third stage are connected. The basic switch includes a part which refers to time information written in a header of an input cell and switches cells to an output port in an ascending order of the time information. In addition, the ATM switch includes a cell distribution part in the basic switch of the first stage. The cell distribution part determines a routes of a cell to be transferred such that loads of routes within the ATM switch are balanced. The ATM switch further includes an adding part which adds arriving time information to an arriving cell as the time information.

Abstract: A multiple phase cell dispatch scheme, in which each phase uses a simple and fair (e.g., round robin) arbitration methods, is described. VOQs of an input module and outgoing links of the input module are matched in a first phase. An outgoing link of an input module is matched with an outgoing link of a central module in a second phase. The arbiters become desynchronized under stable conditions which contributes to the switch's high throughput characteristic. Using this dispatch scheme, a scalable multiple-stage switch able to operate at high throughput, without needing to resort to speeding up the switching fabric and without needing to use buffers in the second stage, is possible. The cost of speed-up and the cell out-of-sequence problems that may occur when buffers are used in the second stage are therefore avoided. A hierarchical arbitration scheme used in the input modules reduces the time needed for scheduling and reduces connection lines.

Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.

Abstract: An economical optical network is constituted by effectively using network resources by using the minimum number of, or minimum capacity of 3R repeaters. 3R section information corresponding to topology information on the optical network to which an optical node device itself belongs is stored, and the 3R section information stored is referred so as to autonomously determine whether or not the optical node device itself is an optical node device for implementing the 3R relay when setting an optical path passing through the optical node device itself. Alternatively, when the optical node device itself is a source node, another optical node device for implementing the 3R relay among the other optical node devices through which the optical path from the optical node device itself to the destination node passes is identified, and this identified optical node device is requested to implement the 3R relay when setting an optical path in which the optical node device itself is a source node.

Abstract: A Pipelined-based Maximal-sized Matching (PMM) scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with a maximal matching scheme. In the PMM approach, arbitration may operate in a pipelined manner. Each subscheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides the matching result. The subscheduler can adopt a pre-existing efficient maximal matching algorithm such as iSLIP and DRRM. PMM maximizes the efficiency of the adopted arbitration scheme by allowing sufficient time for a number of iterations. PMM preserves 100% throughput under uniform traffic and fairness for best-effort traffic.

Abstract: A network is realized having GMPLS and IP/MPLS mixed, in which an IP/MPLS node can be operated as is without replacing the IP/MPLS node with a node having a GMPLS function, even if the GMPLS and IP/MPLS are mixed. To match with the protocol of the IP/MPLS node outside of a GMPLS cloud, the GMPLS+IP/MPLS node (edge) establishes a PSC-LSP between GMPLS+IP/MPLS nodes (edge), uses the PSC-LSP as an IP/MPLS link from the viewpoint of the IP/MPLS node, and operates signaling of an MPLS-LSP establishment requested from the IP/MPLS.

Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.

Abstract: An ATM switch includes a first stage, a second stage and a third stage each of which stages includes at least one basic switch, wherein the first stage, the second stage and the third stage are connected. The basic switch includes a part which refers to time information written in a header of an input cell and switches cells to an output port in an ascending order of the time information. In addition, the ATM switch includes a cell distribution part in the basic switch of the first stage. The cell distribution part determines a routes of a cell to be transferred such that loads of routes within the ATM switch are balanced. The ATM switch further includes an adding part which adds arriving time information to an arriving cell as the time information.

Abstract: An ATM switch includes a first stage, a second stage and a third stage each of which stages includes at least one basic switch, wherein the first stage, the second stage and the third stage are connected. The basic switch includes a part which refers to time information written in a header of an input cell and switches cells to an output port in an ascending order of the time information. In addition, the ATM switch includes a cell distribution part in the basic switch of the first stage. The cell distribution part determines a routes of a cell to be transferred such that loads of routes within the ATM switch are balanced. The ATM switch further includes an adding part which adds arriving time information to an arriving cell as the time information.

Abstract: An ATM switch includes a first stage, a second stage and a third stage each of which stages includes at least one basic switch, wherein the first stage, the second stage and the third stage are connected. The basic switch includes a part which refers to time information written in a header of an input cell and switches cells to an output port in an ascending order of the time information. In addition, the ATM switch includes a cell distribution part in the basic switch of the first stage. The cell distribution part determines a routes of a cell to be transferred such that loads of routes within the ATM switch are balanced. The ATM switch further includes an adding part which adds arriving time information to an arriving cell as the time information.

Abstract: The present invention relates to a node used in an optical communication network, and comprises functions for transferring and receiving data, and a unit for establishing and releasing a cut through path to a node of the next stage, the establishing and releasing unit having a detecting unit which detects the arrival of a request packet for establishing a cut through path to the node stage.

Abstract: To transfer push service traffic efficiently, a packet is given a content identifier for identifying the content of the packet, or is given one or both of this content identifier and a category identifier for identifying the category to which the content belongs; and a user registers in advance in the distribution network content identifier related information or one or both of this content identifier related information and category identifier related information, said information relating to content and/or categories that the user wishes to have sent; and the distribution network passes content, or one or both of content and category, wanted by a downstream user. A table for filtering is set by taking into account content identifier related information that has been notified by a user.

Abstract: To transfer push service traffic efficiently, a packet is given a content identifier for identifying the content of the packet, or is given one or both of this content identifier and a category identifier for identifying the category to which the content belongs; and a user registers in advance in the distribution network content identifier related information or one or both of this content identifier related information and category identifier related information, said information relating to content and/or categories that the user wishes to have sent; and the distribution network passes content, or one or both of content and category, wanted by a downstream user. A table for filtering is set by taking into account content identifier related information that has been notified by a user.

Abstract: A layered network node of which a network it belongs is divided up into cells which are constituted by a plurality of nodes; the cells are defined as virtual nodes; if links exist which connect the interiors of the virtual nodes and the exterior, contact points between them are defined as interfaces of the virtual nodes; the virtual network constituted by the virtual nodes is further divided up into cells and making them into virtual nodes; said virtual network is defined as a network of a higher level with respect to the initial virtual network; by performing said operation of division into cells and making into virtual nodes once or a plurality of times, the layered network is constituted; path computation is performed from the source node to a destination node in a stepwise manner by dispersing it over the various layers.

Abstract: A source node, along with transmitting an optical path setup request, notifies towards a destination node available resource information related to itself, pre-assigns the available resources which its own node has notified. Each of transit nodes, along with relaying towards the destination node the optical path setup request which has been received from a previous hop node, notifies towards the destination node available resource information related to itself, and pre-assigns the available resources which each of their own nodes has notified. The destination node, along with reserving a resource which is to be used for setting up an optical path based upon an optical path setup request which has been received, transmits a resource reservation request towards the source node. The transit nodes and the source node actually reserve an available resource which has been pre-assigned, based upon a resource reservation request from a next hop node.

Abstract: An upper layer node is used in a multi-layer network which includes an upper layer network which performs switching and transfer in units of packets, and a lower layer network which includes optical transmission lines and optical switches and accommodate the upper layer network; this upper layer node being connected to the lower layer network which includes lower layer nodes including obstruction restoration sections, and transmission lines, and including: a section which detects the occurrence of an obstruction upon a transmission line which it accommodates; a section which advertises the detection result as obstruction information; a section which retains the topology information for the network; a section which updates the retained topology information according to advertised obstruction information, or obstruction information which it has detected; and an advertisement transfer section which advertises to other upper layer nodes the advertised obstruction information.

Abstract: A multi-layer photonic network and nodes used therein are provided. The multi-layer photonic network comprises a packet network which performs switching and transfer in packet units, and a photonic network comprising optical transmission lines and photonic switches, and which accommodates the packet network. The multi-layer photonic network also has a two layer structure of optical wavelength links (O-LSPs) and packet links (E-LSPs). The O-LSPs are constituted by the optical transmission lines and comprise optical wavelength switching capability (LSC) which is capable of switching in optical wavelength units and packet switching capability (PSC) which is capable of switching in packet units at both their ends. The E-LSPs include the O-LSPs and PSCs at both their ends. Each node includes a section for automatically establishing an O-LSP according to an establishment request for an E-LSP while taking account of path information including path cost, resource consumption, and traffic quantity.

Abstract: The invention relates to a node, an optical/electrical path integrated network using this node, and a program which controls the node. The node according to the invention is suited to use in an optical/electrical path integrated network constructed from a plurality of electrical sub-networks comprising nodes which are interconnected by electrical paths in which routing is performed based on packet header information and a photonic core network comprising nodes which are interconnected by optical paths, the photonic core network and the plurality of electrical sub-networks being interconnected by optical paths, wherein the node comprises a device which outputs to other nodes, a traffic quantity between the node to which it belongs and other nodes.

Abstract: An optical network includes links and nodes. In each node, a control section sets an optical path to be used for optical transport. A switching section performs switching of the optical path. In the control section, a link observation section observes the wavelength of signal light that is being transmitted through a link connected to the node as the utilization of the link. A flooding section notifies each of the remaining nodes of the link utilization and acquires a link utilization observed by each of the remaining nodes so as to share the link utilization between the nodes. An optical path calculation section selects the optical path to be used for optical transport by calculation using the link utilization observed by the link observation section and the link utilization observed by each of the remaining nodes. An optical path setting section sets the optical path selected by the optical path calculation section to the optical path to be used for optical transport.