Abstract: A router apparatus for performing communication by switching a first and second line, the router apparatus includes: a setting unit which sets a first protection time until the first line is switched to the second line after a line failure in the first line is detected, and a second protection time until the second line is switched to the first line after recovery from the line failure in the first line is detected, to times corresponding to a quality state of the first line, respectively; and a line switching unit which switches the first line to the second line when the first protection time elapses and the line failure in the first line continues, or switches the second line to the first line when the second protection time elapses after the line failure in the first line is detected.

Abstract: “A System, Method, and Device for Facillitating Multi-Path Cryptographic Communication” A system, method, and node device for cryptographic communication are disclosed. Cryptographic tunnels between a source and destination node having intermediate stops at one or more repeating nodes are used to send and receive encrypted packets. This method of cryptographic communication is the default route of message exchange and allows repeating nodes to decrypt and re-encrypt packets along the route. When cryptographic communication traffic at a repeating node exceeds or falls below a certain threshold value, a direct route cryptographic tunnel is established between a source and destination pair of nodes, thereby diminishing encryption and decryption process load at intermediate repeating nodes.

Abstract: The invention relates to a network emulating a local network, and particularly provides a communication cache management device that uses, e.g., an MPOA for efficiently transmitting LAN data within an ATM network, and a method therefor. A communication cache management method at an ingress communication client side includes the steps of: monitoring a data flow that is transmitted to an ingress communication server within a predetermined time period before a time-out of an aging timer after a shortcut has been set; re-starting an aging timer when there has been detected a data flow that exceeds a predetermined value; timing out the aging timer when there has been detected no data flow that exceeds the predetermined value; and timing out the aging timer when the contents of a response message to a communication address resolution request message do not permit a cache refresh.

Abstract: An ATM network system which connects a source terminal equipment to a destination terminal equipment by an SVC through a plurality of ATM communication nodes. In the source ATM communication node, a priority level definition table is preset with priority levels for the SVC whose service category is the UBR service per a physical port, MAC address, or IP address, a control unit transmits a SETUP message including the priority levels, a switch controller controls a readout level of a user's information cell based on the priority levels. In each of the ATM communication nodes having received the SETUP message, the switch controller controls a readout level of the user's information cell based on the priority levels included in the SETUP message.

Abstract: If an illegal cell number is detected three times continuously for a monitor section in a connection, then tag information including class information indicating the lowest quality class is added to a cell in the connection. If a normal cell number is detected four times continuously for the monitor section with the quality class of the cell lowered for the connection, then the quality class of the cell in the connection is restored to its original class. If an illegal cell number is detected n times continuously for the monitor section with the quality class of the cell lowered in the connection, then the tag information including valid/invalid information indicating an invalid state is added to the cell in the connection. As a result, the cell is stopped from being transmitted to a cell switch. If a normal cell number is detected m times continuously with the transmission of cells stopped, then the cell is released from the stop to the transmission of cells to the cell switch.

Abstract: A terminal for a maintenance is connected via a local area network (LAN) to a wideband switching equipment. An address such as an IP address is allocated to each of a plurality of wideband switching equipments, and a virtual channel connection for transferring maintenance data to between the plurality of wideband switching equipments. Each control unit of the plurality of wideband switching equipments is provided with a table for registering an address of a connected party to make the address corresponding to an interface unit accommodating a wideband line. The control unit performs control to select whether to transfer the maintenance data to other wideband switching equipment or to the maintenance terminal connected via the LAN with reference to this table.

Abstract: The invention provides a communication method for realizing communications between different apparatus in a PVC connection type switched network, which is improved in that PVCs in the inside of the switched network can be set efficiently using preset PVCs dynamically to allow high speed communications without complicating the communication protocol. The communication method is applied to a PVC connection type switched network wherein a plurality of transmission apparatus and at least one reception apparatus are connected to each other by PVC connections by way of an exchange switch which handles fixed length cells. According to the communication method, one or more of the transmission apparatus which have acquired an access right to a PVC to be used performs transmission to the reception apparatus using respective transmission line bandwidths.

Abstract: If an illegal cell number is detected three times continuously for a monitor section in a connection, then tag information including class information indicating the lowest quality class is added to a cell in the connection. If a normal cell number is detected four times continuously for the monitor section with the quality class of the cell lowered for the connection, then the quality class of the cell in the connection is restored to its original class. If an illegal cell number is detected n times continuously for the monitor section with the quality class of the cell lowered in the connection, then the tag information including valid/invalid information indicating an invalid state is added to the cell in the connection. As a result, the cell is stopped from being transmitted to a cell switch. If a normal cell number is detected m times continuously with the transmission of cells stopped, then the cell is released from the stop to the transmission of cells to the cell switch.

Abstract: In a method of communicating between an ATM-UNI and a LAN in a communication apparatus, which has an ATM-UNI interface and a LAN interface for performing communication between these interfaces via an ATM switch, transmission data in an ATM-cell format is received from a terminal connected to the ATM-UNI interface to a terminal connected to the LAN interface. The ATM cells are accumulated in a buffer memory provided in the ATM-UNI interface and assembled into a frame. Completion of reception of all ATM cells of one frame is recognized and it is determined whether there is margin for a transmission by referring to a status of vacancy of a LAN interface corresponding to the other party to communication. One frame of the ATM cells accumulated in the buffer memory is transferred to the LAN interface corresponding to the other party via the ATM switch in a case where there is margin for transmission. The ATM cells are converted into a frame at this LAN interface and the frame is sent to a LAN terminal.

Abstract: Disclosed is a PBX system connected through a communication line (61) to an ISDN public network (101), comprising a control unit connected to a PBX switching network. The control unit comprises a unit for adding a line accessing number (.alpha.) to a calling party address (#B) in an incoming call information (ii) received through the communication line so as to form an incoming information (iii) to be received by said extension terminal, and a unit for transmitting the incoming information including the line accessing number to the extension terminal in which the line accessing number is displayed, whereby the user can recognize whether the incoming call is from the ISDN public network or from another extension terminal accommodated by the PBX system.