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: An OVPN user register an L1 signal type information which is used in the user's device in an OVPN terminating device in advance together with an IP address and a VPNID which are allocated to the user's device. Registered contents are notified to other OVPN terminating devices which control the same VPNID as that of the user's device. Otherwise, when a calling connection request arrives from the user's device, the registered contents are notified other OVPN terminating devices which control the devices which receive the notification. By doing this, it is possible to handle a request by the user for changing the setting for the signal format which is employed in the user's device quickly. Also, it is possible to realize an OVPN which can perform a process for a calling connection request from the user efficiently and improve an operability for the 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 local switch serving a terminal constituting the destination of an IP packet is identified from the IP address of the packet, and time slot switching information is formed, this being information relating to a route through an STM network to this local switch. The packet can then be transferred through the STM network in accordance with this time slot switching information. As a result, a packet with an IP address can be transferred through an STM network.

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: Nodes notify each other of the availability situation of links, whereby the link availability situation is reflected in the network topology information held by each node. The designated routing information of a packet which arrives at a local node for subsequent transfer is updated on the basis of the topology of a network from which the following have been removed: any nodes which a packet arriving at the local node for subsequent transfer has already passed; any links directly connected to such nodes; and any congested or faulty links.

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: 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.

Abstract: The present invention relates to a node, a packet communication network, and a packet communication method and program. The node of the present invention is one which includes a section which advertises to other nodes link state information which indicates the state of links which are connected to this node, a section which establishes a packet forwarding path according to the link state information which is included in the advertisement by the advertisement section, and a traffic observation section which observes the traffic and outputs its observations as traffic observation results.

Abstract: The present invention relates to a node which is used in the structure of an optical communication network. This node has a signal transmission function for performing data transfer and a signal receiving function for performing data signal reception, and includes a unit for establishing and releasing a cut through path to a next stage node. Moreover, it includes a unit for detecting the arrival of a leading packet of burst data, and the unit for establishing and releasing the cut through path includes a unit for establishing a cut through path to the next stage node, when the arrival of a leading packet of burst data is detected by the leading packet arrival detection unit.

Abstract: An ATM switch includes a plurality of stages in which each stage has basic switches and the stages are interconnected. The ATM switch includes M×N basic switches per each stage and a part for interconnecting between the stages. The M×N basic switches are divided into N groups. The part connects an output port of each basic switch at a front stage to M input ports of the basic switches at a back stage. At the output port, a wavelength-multiplexing part is used, and, at the input port, a wavelength-demultiplexing part is used. Further, a wavelength-switching part for switching optical signals of M wavelength-multiplexed optical signals arriving from the M wavelength-multiplexing part and outputting the switched wavelength-multiplexed optical signals to the M wavelength-demultiplexing part is used.

Abstract: This invention relates to a node, comprising a data transferring function for transferring data, a data receiving function for receiving data, and an establishing unit for establishing and releasing a cut through path to a node of a next stage; the establishment and releasing unit comprising a calculating unit which calculates in advance establishment paths of a cut through path to each of a plurality of nodes in the next stage, and a detecting unit which detects the arrival of a leading packet of burst data; and the calculating unit calculating establishment paths of a plurality of cut through paths in accordance with an IP address of the leading packet, detected by the detecting unit.

Abstract: In an STM network, burst data which has been given a logical address is transferred using time slots allocated to the physical address of the destination, this physical address corresponding to the logical address. This enables data to be communicated over the STM network using logical addresses.

Abstract: In a best effort type service of an ATM communication network for circulating an RM cell, a subscriber's switchboard holds the latest route information, and the RM cell is used for short distance communication between the communication terminal and subscriber's switchboard. For a plurality of connections accommodated in the switchboard and using a transmission line or a route in common, information on the allowable transmission rate, the actual transmission rate, the full bandwidth and full input bandwidth of the transmission line or the route, and the number of connections using in common the transmission line are collected and held. A transmission rate acceptable for the caller's terminal is calculated for each connection on the basis of the information. An increase of a memory capacity is restricted by providing a common buffer and managing it by a pointer value. A list of cells which have arrived simultaneously is prepared, and is managed by the pointer value.

Abstract: A contention control circuit which temporarily stores cells arriving from a respective plurality of input lines to output cells to a single output line without collisions. The contention control circuit compares, at each input line in turn, the priority of the cell that has arrived from that input line, with the priority of the cell selected from among the cells that have arrived from preceding input lines as the cell having the highest priority, and again selects the cell with the higher priority.

Abstract: An ATM switch includes a plurality of input line corresponding units, a plurality of output line corresponding units, and a wavelength shifting unit. The wavelength shifting unit is arranged between the input line corresponding units and the output line corresponding units to shift optical signals having different wavelengths in a plurality of wavelength-multiplexed optical signals arriving from the input line corresponding units and output the wavelength-multiplexed optical signals. Each input line corresponding unit includes an input-side basic switch for distributing N (N is a positive integer) cells respectively input to input ports to N lines, an electro-optic converter for converting the cells into optical signals having different wavelengths in units of N lines, and a multiplexer for multiplexing the optical signals into one wavelength-multiplexed optical signal.