Abstract: In a private branch exchanger which is connected to an ISDN network, a virtual private line information table stores information indicating channels corresponding to virtual private lines in units of routes. An identifying unit determines a route in response to an event, refers to the virtual private line information table based on the determined route to determine a specific one of the channels corresponding to the virtual private lines for the determined route. Also, the identifying unit determines whether a connection of a specific virtual private line corresponding to the specific channel to an ISDN network is established. When the specific channel corresponding to a specific virtual private line is usable, the identifying unit issues a communication instruction. A communication unit performs communication using the specific channel corresponding to the specific virtual private line in response to the communication instruction.

Abstract: The present invention provides a method of controlling a call between nodes in a distributed node exchange network having interconnections of plural exchanges, wherein a distributed node has a channel switch, a subscriber circuit, a trunk circuit accommodating local lines and private lines and a processor for controlling a call of the nodes. In a case of connections between the nodes, the node call control processor accommodating call extension lines and the other node call control processor accommodating receiving extension line in correspondence to the call extension lines carry out distributed processings of the call control for providing substantially the same connection services as the interconnection in the node.

Abstract: An exchange is provided. Particularly, an office data management system where exchanges in a switching network can be operated and managed in common, a system for assigning personal numbers to subscribers, and a same subscriber's number migrating system where the same subscriber's number can be used even after a subscriber is sifted from an exchange to another are provided. Each node exchange includes a numbering plan inherent to a node, individual office data storing extension information, a numbering plan common to the entire network, and a common office data storing extension information. A certain exchange acting as a master in a station allots a copy of the common office data to each node via a data-link control circuit (FCCH) that transmits and receives call control signals and maintenance signals.

Abstract: In an ATM relay system comprising an ATM network (30) and a plurality of private branch exchange systems each of which comprises a switching system (11, 12, 13) and an ATM multiplexing unit (21, 22, 23) connected to the ATM network (30), the switching system (12) comprises a central control unit 46 for delivering an interchange indication signal to said ATM multiplexing unit (22) on carrying out a relay connection from the ATM network (30) to the ATM network (30). Responsive to the interchange indication signal, the ATM multiplexing unit (22) carries out an interchange operation.

Abstract: A connection system of a public network subscriber and a private network subscriber in ISDN includes a first PBX for connecting the public network subscriber and the public network, a second PBX for the private network subscriber and the private network, and third PBXs for connecting the public line and the private line. The first PBX selects one of the third PBXs as an access point to the private network, and forms a first set-up message having the public line number of the selected access point as a destination, the received private line number as a sub-address, and the public line number of the public network subscriber as a calling party identification. The second PBX selects one of the third PBXs as an access point to the public network, and forms a second set-up message having the private line number of the selected access point as a destination, the received public line number as a sub-address, and the private line number of the private network subscriber as a calling party number.

Abstract: In a private branch exchange, PBX line interfaces, a tie trunk interface interfacing a distant PBX, an ISDN interface interfacing a public switched ISDN network, and speech codecs are connected to a switch. Each speech codec provides data-rate conversion between a 64-kbps signal and a lower bit-rate signal. A mux/demux unit is connected between the codecs and the switch for multiplexing the lower bit rate signals from the codecs into a multiplex signal and demultiplexing a multiplex signal into lower bit rate signals for coupling to the codecs, respectively. The switch is controlled in response to a call from a PBX telephone to establish a connection between a line interface and any of the codecs and a connection between the mux/demux unit and the tie trunk interface when the distant PBX is the destination. If the call is destined to an ISDN user, a connection is established between the line interface and the ISDN interface.

Abstract: For controlling an incoming call transmitted from an integrated services digital network towards a terminal unit, an exchange comprises a memory for memorizing address data representative of slave addresses which are assigned to the incoming call. In accordance with the incoming call and the address data, a local signal producing circuit produces a local signal for use in making a control portion of the exchange control the incoming call. When the incoming call includes a kind datum representative of a kind of the terminal unit, such as speech, facsimile, and/or data processing units, the control portion controls the incoming call in accordance with the kind datum and the address data. Likewise, the incoming call may include a channel datum and a number datum.

Abstract: ISDN subscriber line interface circuits of a switching system serve customer premises equipment of different information transfer capabilities. Least cost routing data and corresponding digit conversion data are stored in a memory, with the routing data indicating least cost outgoing routes through an ISDN network. These data are retrieved from the memory according to the called party number and information transfer capability field of a call setup message received from a calling party. The called party number is then converted according to the retrieved digit conversion data, and an ISDN trunk circuit is selected according to the retrieved least cost routing data. A connection is established between the originating ISDN SLIC and the selected ISDN trunk circuit, and the converted called party number is transmitted through a signaling channel to the ISDN network.

Abstract: In a private network where PBXs (1, 2) are connected through a primary rate interface (47, 48) to an ISDN network (45), one of the PBXs has routing data for virtual tie trunks for signaling and speech transmission, respectively, to be established via the ISDN to a distant PBX (2), and channel status data indicating their set-up or clear-down state according to time of day and calendar day. The stored data is periodically accessed, and depending on the contents of the channel status data, a call setup or clearing message is sent from the PBX (1) to the ISDN to set-up or clear-down the virtual tie trunks. On receipt of a response from the distant PBX, busy/idle status of the virtual tie trunks is changed according to the accessed channel status data. In response to a request from a user station, a path is established therefrom to the virtual speech tie trunk and a call setup message is sent direct to the distant PBX through the virtual signaling tie trunk.