Abstract: There is disclosed a transmitting system which is capable of recovering a fault efficiently, thereby improving transmission quality. When a fault has occurred, a fault message-sending section notifies a fault message including information of a detected location of occurrence of the fault to other devices. A relay/transfer section carries out label switching operation on a packet having a label added thereto and relay/transfer of the packet. The integer calculation section performs a function operation based on flow information of an input packet to calculate one integer corresponding to one input packet. A path-setting section classifies the calculated integer into one of sections divided by boundary values and sets the section as a path for transferring the input packet. Further, the path-setting section adjusts the boundary values, when a fault message is received, or depending on the state of communication.

Abstract: The present invention relates to distributing the load between the set routes among a plurality of routes between a communication apparatus which serves as a start point to another communication apparatus which serves as an end point. An apparatus provided in a router in a network collects traffic characteristics of transmission paths connected to the router, notifies other routers of the collected traffic characteristics, calculates load based on the collected traffic characteristics, decides based on the calculated load information whether or not a transmission path should be added or deleted, and equalizes the load among the plurality of transmission paths.

Abstract: The present invention provides a traffic information collecting device and method. A node in a communication network collects a first traffic information of a first link connected to an own node. And also the node receives second traffic information of second links connected to the other nodes. The second traffic information is transmitted from the other nodes. The node stores the first and second information. In consequence, the node can be informed of the conditions of the traffic of each link in the communication network based on the stored information. As the result, it becomes possible to control the load sharing in correspondence to the conditions of the traffic.

Abstract: An L bit for notifying another router of whether a self-router belongs to a connection-oriented network is newly provided in the options field of a conventional OSPF packet and the OSPF packet, including L bit is transmitted to another router. In this way, each router belonging a network can automatically recognize a router belonging to a connection-oriented network by detecting L bit. Then, by generating a routing tree, a connection-oriented network device can be identified in the routing tree and mapping between a connection-oriented network and a connectionless network can be performed in an edge device.

Abstract: A packet flow control apparatus performing flow control of packets each having variable length, includes: a buffer memory for temporarily accumulating arrived packets until a sending time of each packet; a counter updated based on a rate determined in accordance with a packet length calculated by a counter value of the counter and limited flow of packets; a sending time determining section for determining the sending time of each packet based on the counter value and a present time; and a sending order control section for managing a sending order of each packet accumulated in the buffer memory, and for sending a read instruction of each packet to the buffer memory, based on the sending time determined by the sending time determining section.

Abstract: A transmission apparatus which can enhance the transmission quality and reliability by establishing a recovery-path efficiently at a high speed for failure circumvention. A recovery-path request message control block generates, sends, and receives a recovery-path request message containing failure location information and recovery-path setup information. A label assignment message control block generates, sends, and receives a label assignment message. A setup label information generation block generates setup label information. A recovery-path label table management block constructs and manages a recovery-path label table. A failure detection block detects the location of a failure. A failure notification message transfer block transfers a failure notification message containing failure location information.

Abstract: A method of detecting a failure in a network, which includes a transport plane comprised of a plurality of communication nodes performing optical cross-connect and a control plane comprised of a plurality of control nodes that are connected to and control the respective communication nodes, includes the steps of transmitting, from a control node connected to a communication node having detected a failure to an adjacent control node, a failure information message having a time indication indicative of a time at which the failure is detected, and identifying, at a given control node which received the failure information message, a location of the failure in response to the time indication.

Abstract: A method and apparatus for selecting paths to route incoming traffic through a data communication network, which is capable of effectively dispersing the traffic load to the selected paths on the network and effectively optimizing the use of network resources. In a communication network, a plurality of label switched paths between an ingress node and an egress node are provided. Incoming traffic at the ingress node is labeled and delivered through the network to the egress node. In a method and apparatus for selecting paths to route the incoming traffic through the network, a plurality of forwarding equivalent class elements (FEC) of the incoming traffic at the ingress node are allocated for the plurality of label switched paths. The labeled traffic is delivered on the plurality of label switched paths on an FEC-element basis so as to route the labeled traffic through the network to the egress node.

Abstract: A boundary apparatus on the transmission side provided on the boundary between an IP network accommodating a transmitting terminal and an ATM network separates the requests for bandwidth which are received from receiving terminals via boundary apparatuses on the reception side into a plurality of groups on the basis of a required bandwidth, establishes a point-multipoint connection between the boundary apparatus on the transmission side and each of the boundary apparatuses on the reception side for each group, and transmits the data from the transmitting terminal to each of the receiving terminals via the connection.

Abstract: In an ATM switching system, an ABR service is implemented with a specific ABR control capability. A subscriber line processing device includes calculating a turnaround delay time of a cell, based on a period during which the cell doubles back at a terminal. A switch or a demultiplexer capable of detecting congestion. A rate calculator calculates a transmission rate corresponding to an output channel, and writes the calculated rate to the cell. A rate changer changes the transmission rate according to congestion. The rate changer counts the number of communicating connections. Then the number of communicating connections which should exist in a certain predetermined period is estimated based on the counted number of communicating connections. A coefficient is determined based on the estimated number of communicating connections and an actual number of communicating connections, and a next estimated value is estimated using the coefficient.

Abstract: Control messages for securing a communication quality are exchanged via a dedicated connection within an ATM network when a sending terminal in an IP network delivers data to a receiving terminal in another IP network via the ATM network. A resource reservation message sent from the receiving terminal is parsed by a boundary device located at the boundary between the IP and the ATM network, and a data transfer connection is established within the ATM network based on the information of the resource reservation message.

Abstract: There is disclosed a transmitting system which is capable of recovering a fault efficiently, thereby improving transmission quality. When a fault has occurred, a fault message-sending section notifies a fault message including information of a detected location of occurrence of the fault to other devices. A relay/transfer section carries out label switching operation on a packet having a label added thereto and relay/transfer of the packet. The integer calculation section performs a function operation based on flow information of an input packet to calculate one integer corresponding to one input packet. A path-setting section classifies the calculated integer into one of sections divided by boundary values and sets the section as a path for transferring the input packet. Further, the path-setting section adjusts the boundary values, when a fault message is received, or depending on the state of communication.

Abstract: The present invention provides a traffic information collecting device and method. A node in a communication network collects a first traffic information of a first link connected to an own node. And also the node receives second traffic information of second links connected to the other nodes. The second traffic information is transmitted from the other nodes. The node stores the first and second information. In consequence, the node can be informed of the conditions of the traffic of each link in the communication network based on the stored information. As the result, it becomes possible to control the load sharing in correspondence to the conditions of the traffic.

Abstract: The present invention relates to distributing the load between the set routes among a plurality of routes between a communication apparatus which serves as a start point to another communication apparatus which serves as an end point. An apparatus provided in a router in a network collects traffic characteristics of transmission paths connected to the router, notifies other routers of the collected traffic characteristics, calculates load based on the collected traffic characteristics, decides based on the calculated load information whether or not a transmission path should be added or deleted, and equalizes the load among the plurality of transmission paths.

Abstract: An L bit for notifying another router of whether a self-router belongs to a connection-oriented network is newly provided in the options field of a conventional OSPF packet and the OSPF packet, including L bit is transmitted to another router. In this way, each router belonging a network can automatically recognize a router belonging to a connection-oriented network by detecting L bit. Then, by generating a routing tree, a connection-oriented network device can be identified in the routing tree and mapping between a connection-oriented network and a connectionless network can be performed in an edge device.

Abstract: A packet flow control apparatus performing flow control of packets each having variable length, includes: a buffer memory for temporarily accumulating arrived packets until a sending time of each packet; a counter updated based on a rate determined in accordance with a packet length calculated by a counter value of the counter and limited flow of packets; a sending time determining section for determining the sending time of each packet based on the counter value and a present time; and a sending order control section for managing a sending order of each packet accumulated in the buffer memory, and for sending a read instruction of each packet to the buffer memory, based on the sending time determined by the sending time determining section.

Abstract: In a first UPC, a PCR is set as a monitor rate for each connection. If a transfer rate of a cell exceeds the PCR set for the connection, the cell is discarded. In a second UPC, an ACR is set as a monitor rate for each connection. If the transfer rate of the cell exceeds the ACR set for the connection, a lower priority is assigned to that cell. Additionally, with a configuration where one UPC monitors a varying rate, a parameter change process is controlled by obtaining a time between a passage time of a detected B-RM cell and an arrival of a user cell and comparing the obtained time with maximum and minimum delay standard values. A parameter table including some parameters is provided. A header of an arrived cell in a forward direction is extracted, and it is determined whether or not the arrived cell is a violation cell using the leaky bucket algorithm, etc. If the arrived cell is a violation cell, it is discarded.

Abstract: Specific ABR control capability for implementing an ABR service in an ATM switching system. A subscriber line processing device has a capability for calculating a turnaround delay time of a cell, based on a period during which the cell loops back at a terminal and returns. A switch or demultiplexer has a capability for detecting congestion. A rate calculator calculates a transmission rate corresponding to an output channel, and writes the calculated rate to the cell. A rate changer suitably changes the transmission rate according to the degree of occurrence of congestion. Additionally, the rate changer counts the number of communicating connections. At this time, the number of communicating connections which should exist in a certain predetermined period is estimated based on the counted number of communicating connections, which is counted in a period shorter than the predetermined period according to a predetermined method.

Abstract: An ATM connection is a virtual communication path specified by VPI/VCI. A plurality of ATM connections that are directed to the same output line is defined as an ATM connection group. A connection UPC (Usage Parameter Control) facility is provided for each of the ATM connections and a connection group UPC facility is provided for the ATM connection group. The connection UPC facilities and the connection group UPC facility are operated in either the monitor mode or the control mode. In the monitor mode, when the rate of flow of packets into a network exceeds a threshold, a control unit is informed of it, but cells are allowed to enter the network as they are. In the control mode, when the rate of flow of cells into the network exceeds the threshold, cells the flow rate of which exceeds the threshold are discarded.

Abstract: A feedback control apparatus whereby the traditional single control loop for available bit rate (ABR) connections is segmented into a plurality of loops that are handled in a mutually related manner for better responsiveness of ABR connection feedback control. Three control loops are illustratively formed: a closed upward feedback control loop between a source end system and a virtual destination-link unit (VD-L) for an ABR connection, a downward control loop between a destination end system and a virtual source-link unit (VS-L) for the ABR connection, and an intra-switch feedback control loop between an upstream virtual source-internal unit (VS-I) and a downstream virtual destination-internal unit (VD-I) for the ABR connection.