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.

Abstract: A switching architecture interconnecting remote switches to a central processor via standard links which may be set up through any number of intervening switching systems utilizing standard switching procedures. The standard links are ISDN links that may be set up dynamically via switching networks within the switching system or via the public switching network. The fact that an ISDN goes through a portion of the switching system or the public switching network is transparent to both the central processor and remote switch. Upon detecting that a primary central processor is no longer in control, each remote switch attempts to obtain an alternate path to the primary central processor. If a remote switch is unable to obtain an alternate path to the primary central processor, the remote switch switches to an alternate central processor on the assumption that the primary central processor has failed.

Abstract: The present invention provides a duplex structure signal transfer point system for common channel signaling system No. 7, which includes a serial duplexed interconnection device; a duplexed network interface connected to the serial duplexed interconnection device, for performing an interconnection between signal message processing submodules; a parallel duplexed interconnection device connected to the duplexed network interface, for performing a parallel duplexed interconnection between unit level 2s and a duplexed unit level 3, wherein the duplexed unit level 3 is connected to the parallel duplexed interconnection device, for performing a protocol level 3 of a message transfer protocol in the common channel signalling system No. 7; and wherein the unit level 2s are connected to the parallel duplexed interconnection device, for performing a protocol level 2 of the message transfer protocol in the common channel signalling system No. 7.

Abstract: A process is disclosed for routing service requests through a network comprising nodes interconnected with links. The network is also arranged so that each node may communicate with each of the other nodes. At preselected time intervals, sets of routes through the network are generated in response to the network configuration and traffic information. Also, at predetermined time intervals, occupancy factors are computed as determined by the network configuration and in response to traffic information. These occupancy factors are proportional to unassociated occupancy factrors and allocation factors associated with calls of the various node-pairs; each of these latter factors is derived from a nominal routing scheme in which a call of the corresponding node-pair is treated as lost only if it is blocked on all of its permitted routes. At predetermined intervals, traffic usage data is measured.

Abstract: A multi-node telephone network having at least caller-controlled interfaces for providing automatic voice messaging. A first caller-controlled interface unit is preferably located in a trunk or line between the calling station and a first switch for providing intercept and redirect functions associated with automatic voice messaging. The first switch is connected to a second switch via one or more digital communication links. A second caller-controlled interface unit is located in one of the digital communication links for providing intercept and redirect functions associated with automatic voice messaging. According to the invention, each of the interface units includes arbitration control circuits responsive to predetermined signaling to determine which of the interface units will provide the intercept and redirect functions upon call initiation to the called station by a caller at the calling station. The predetermined signaling is preferably provided in a common channel signaling No. 7 (SS7) protocol.

Abstract: A method of displaying the information on a called party on a calling terminal, and a communication network using this method. In a communication network structuring an inter-station network by using a signalling system capable of transmitting a call control signal including additional information, a user of the called party terminal registers its own information in its exchange beforehand. An activation signal from an originating exchange to a destination exchange is added to a representation indicative of a request type whether a call is made or not made. A call control signal from the destination exchange to the originating exchange, such as an address completion signal, is added to a parameter representative of the registered information. These signals are transmitted between the originating and destination exchanges so that the originating exchange displays the received, registered information of the called party on the calling party terminal.

Abstract: The invention relates to upgrading existing telephone central offices having 1ESS or 1AESS switching equipment to utilize the SS7 protocol. In particular, the 1ESS and 1AESS switching equipment is provided with the capability of controlling the connection, management, and disconnection of telephone circuits using Signaling System Number 7 (SS7), a national and international standard set of protocols for providing such circuit control and providing and receiving information via the SS7 protocol for enabling enhanced service in the switching equipment.

Abstract: In a telecommunication system having a plurality of cooperating exchanges and using a separate signaling network, an existing exchange is replaced by a new exchange by a piecemeal transferring of interexchange trunks from the existing exchange to the new exchange and testing the trunks on the new exchange. All signaling messages pertaining to trunks originally resident on the existing exchange are addressed to the existing exchange, are intercepted and are selectively forwarded to the new exchange on the basis of recorded data defining trunks moved to the new exchange. One embodiment uses a point code converter connected between a signal transfer access point for the signaling network and both the old and the new exchange. The converter receives all messages addressed to the existing exchange and transfers the messages to either the old or the new exchange, depending on the present location of the trunk.

Abstract: The present invention describes an automatic voice messaging system for use in a telephone network having a calling station connectible to a first switch and a called station connectible to a second switch, with the first and second switches connected by a digital serial link. The voice messaging system preferably comprises an interface, a detection circuit, a speech circuit and a control circuit. The interface monitors signals on the digital serial link. The detection circuitry is connected to the interface for detecting busy or ring/no answer conditions at the called station upon call initiation to the called station from the calling station, and for detecting receipt of a predetermined code from the calling station indicating that the caller desires to leave a message for the called station. The speech circuit is also connected to the interface for issuing a predetermined prompt to a user of the calling station.

Abstract: An electronic switching system having a call-forwarding function for effecting call forwarding between subscribers. Discrimination information is added to call forwarding data for respective subscriber terminals. The discrimination information indicates whether or not each of the subscriber terminals is already registered as an elternative destination from the other subscriber terminals. When a call forward to one of the subscriber terminals is to be registered, the corresponding discrimination information is read. When the read discrimination information indicates that the subscriber terminal is not yet registered as an alternative destination, the subscriber terminal is allowed to be registered as an alternative destination. When the read discrimination information indicates that the subscriber terminal is already registered as an alternative destination, the subscriber terminal is inhibited from being registered as an alternative destination.

Abstract: Casting of votes takes place by the dialing of a subscriber number of a stated destination switching center. By omitting establishing a connection to the destination switching center in the source switching center only the appropriate connection requests are summed and, after a predetermined sum value has been reached or after a given length of time has passed since the beginning of the vote taking, the particular sum value is signaled to the destination switching center via the common signal channel.

Abstract: This invention relates to arrangements for providing a new spontaneous voice message service to any telephone customer at any telephone station when that customer encounters any destination that is busy or that does not answer. When a customer having a dual tone multifrequency (DTMF) station calls any destination that is busy or does not answer, the customer is invited, via an announcement identifying the new service, to record the caller's voice message. The announcement accompanies the returned busy tone or audible ring signal. The customer keys *867(=*VMS) and is then connected to a Voice Message Operations Center (VMOC) which prompts the customer to record the message. Advantageously, customers need not redial a VMOC number, their own number, and a destination number to reach a VMOC for storing the video message; the added convenience of this arrangement should stimulate substantial additional use of voice message service.

Abstract: In a private communication network (10) served by a provider of call interconnection services, e.g., a carrier service node (15), the number of trunks (50-52) used within a call path is reduced without affecting the private nature of the private network. The service provider serves customer calls by means of a service node controller (SNC 40)--a switch such as a PBX. The SNC directly interconnects trunks (50,51) that connect it with a call-source and a call-destination node (20,21) of the customer, without routing the call through the customer's tandem node (24). The SNC merely queries the customer's tandem node over a control link (53), such as an ISDN D channel, to obtain requisite call-routing information from the customer's database (60). The customer retains ownership and control of the tandem node and its database, thereby preserving the private nature of the private network.

Abstract: The invention relates to upgrading existing telephone central offices which utilize electromechanical or electronic switching equipment incapable of using the SS7 protocol. In particular, it relates to providing the switching equipment with the capability of controlling the connection, management, and disconnection of telephone circuits using Signaling System Number 7, a national and international standard set of protocols for providing such circuit control and providing and receiving information via the SS7 protocol for enabling enhanced service in the switching equipment.

Abstract: In a telephone switching apparatus having an inter-office interface consisting of a plurality of communication circuits having different priorities and a control line for transfer of call control signals, a first circuit having the highest priority is hunted from the idle one of said communication circuits upon setting of a call and the communication is started. During the communication, if a second circuit having a higher priority than that of the first circuit becomes idle, by communicating a control signal to switch the circuit between the switching apparatuses, the busy circuit for the call is switched from the first circuit of a low priority to the second circuit of a high priority.

Abstract: A method of operation of a telephone and data PABX communication network which comprises a set of nodes interlinked by means of TDM-transmission lines. Each node serves an individual switching exchange and comprises its own control module. To a user the network is manifested as a single system. The invention flexibly sub-divides such a system, allowing the offering of fully integrated specific facilities within the boundaries of domains that can be arbitrarily defined within the total network configuration. Local data is provided in each node for a specific facility-bounded program which dictates the operation of a control module of the node. Such data contains an adjustable address file having the addresses of those nodes over which a call or a specific facility to which such program relates can be accepted. Nodes to which a specific facility is extended and whose addresses are incorporated in the file of each such node define a fully integrated domain wherein the relevant specific facility can be offered.

Abstract: A device for detecting a specified signal on a conventional telephone line includes a pair of input terminals to which to connect a pair of conventional telephone lines, and a circuit connected to the input terminals that draws a different amount of power from a separate power source when the specified signal is present across the input terminals thant it draws otherwise. A transformer couples the power supply to the circuit while isolating the power source from the input terminals, and power sensing circuitry that senses a difference in power supplied to the transformer generates a control signal that is also isolated from the input terminals.

Abstract: A circuit arrangement for telecommunication installations, in particular, telephone exchange installations is disclosed in which type information is sent ahead of each communication to be transmitted. In bidirectional communication transmission with different possible communication types, type information announcing the respective communication type is sent ahead. In the receiving equipment the beginning of the arrival of type information is recognized and immediately, that is, almost simultaneously, an assortment of type-specific message corresponding to each of the possible communication types is transmitted in the opposite direction, of which each indicates the readiness or non-readiness for receiving a communication of the respective type.

Abstract: A system for interconnecting a pair of communication systems comprising a pair of expansion switching matrices connected to bidirectional signal ports of the respective communication systems and interconnected via a plurality of signal paths, such as junctors. Control information is transmitted between central controllers of the pair of communication systems via a pair of serial data transmission circuits, such as universal asynchronous receiver/transmitters. Thus, predetermined ones of the signal ports of the separate communication systems may be interconnected via the expansion switching circuits independently of signal traffic within the respective communication systems. In addition, special features such as call ring back busy, may be implemented between signal ports of the respective communication systems as a result of control information being communicated via the serial data transmission circuits.

Abstract: A telephone communication system comprising a plurality of intercoupled sub-systems each of which comprises a control-unit and at least one peripheral module to which multiple terminals are connected. The control-unit of each sub-system includes destination numbers identifying the terminals within the system, and from the destination number provided by a source terminal determines with which sub-system the destination terminal is associated. When the destination terminal sub-system differs from the source terminal sub-system, signalling information identifying the source terminal is transmitted to the control-unit of the destination terminal sub-system. The control-unit of the destination terminal sub-system then analyzes such information and establishes the connection to the destination terminal therein.

Abstract: In each case, a common interface module is assigned to subscriber lines and/or trunk groups. This interface module is connected both to the speech path switching network and, via a data transmission trunk group, to a central controller which establishes the switching paths. The information is transmitted via the speech path switching network using pulse code modulation. To provide central control for the telephone exchange, the information is transmitted via a data transmission trunk group using a message format with variable data length (HDLC procedure). Each interface module is assigned an interface circuit for transmitting information to and receiving information from the connected subscriber lines and/or trunk lines, for buffering speech and signal information, and for monitoring status. Speech and signal information are transmitted based upon the control commands of the central controller and based upon a peripheral controller assigned to the interface module.

Abstract: Common channel interoffice data transfer circuitry is shown for transmitting and receiving both analog and digital CCIS data. This data transfer circuitry is a data terminal equipment control circuit. The terminal equipment control circuit is microprocessor controlled. The terminal equipment control circuit is adaptable to transfer CCIS data to analog interfaces, such as modems. The circuit is also adaptable to transfer CCIS data to and from digital data sources, such as digital trunks or T1 spans. The design of this circuit possesses a high degree of commonality and, therefore, requires a minimal amount of components.

Abstract: A nonhierarchial switching system employing a modified unified algorithm for developing link sizes for paths that connect switches in the system and routing sequences for the switches in the system, and further employing means for updating the routing sequences to minimize potential blocking in the network. In one embodiment, the modified unified algorithm develops improved link size determinations by taking advantage of traffic sensitive dynamic routing on the alternate paths available in the nonhierarchial switching system for connecting any switch to any other switch in the system. Updating of the routing sequences is achieved in that embodiment by evaluating the least loaded path for each potential connection of two switches in the system and, when appropriate, by installing the least loaded path as the second choice path in the routing sequence for that potential connection.