Abstract: A channel monitoring system for monitoring a multiplicity of transmission lines including a plurality of channel monitors, a line assignment controller operative to determine a subset of the plurality of channel monitors to be assigned to monitoring an individual transmission line, an access switch operative, in response to an input from the controller, to connect the individual transmission line to the preferred number of monitors from among the plurality of channel monitors.

Abstract: A call saving system for an ISDN telephone switching system includes a subscriber switching unit and terminal units connected to the subscriber switching unit via subscriber lines. A control device controls an overall call saving process executed between the subscriber switching unit and each terminal unit when a restart process is started after a call process is temporarily stopped. When a restart process is started, a restart message is transmitted to each terminal units on the basis of the presence/absence of a call to be saved. Each terminal unit includes a call state setting circuit for a state display message when information indicating a confirmation of a call saving is set in the restart message.

Abstract: An electronic exchange apparatus which is maintained by remote control based on information supplied from a maintenance terminal through a communications network, comprises a memory for storing called party number information representing a number for maintaining the electronic exchange apparatus and calling party number information representing a number of the maintenance terminal for allowing a maintenance operation, and a controller for, when a call is received from the communications network, detecting whether called party number information and calling party number information included in a message transmitted together with the call, coincide with the called party number information and the calling party number information stored in the memory, respectively, and for, when the information included in the message coincides with the information stored in the memory, recognizing the call as a maintenance call for maintaining the electronic exchange apparatus, thereby setting the electronic exchange apparatus

Abstract: An international telecommunications network includes a set of international exchanges located in a particular country which connect a national telecommunications network situated in that country with networks situated in other countries. The international network includes a traffic management system having an expert system with a set of knowledge sources. An identifier identifies alarms relating to traffic and a prioritizer arranges the alarms in order of priority. A diagnoser diagnoses the cause or causes of the alarms by proposing suspected causes and investigating them in relation to traffic and network data. A resolver proposes remedies for the causes of the alarms by reasoning over each cause in relation to data on traffic associated with the cause, reasoning over each remedy in relation to data on traffic in the neighborhood of the remedy to determine a figure of merit for the remedy, and then arranging the remedies in order of merit.

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: A remotely controlled telephone system terminal box provides non-blocking connectivity between any selected unassigned pair of a plurality X of distribution pairs of lines and any selected plurality Y of drop pairs of lines and employs a plurality X of multiple-position rotary stepper switch blocks each driven by a stepper motor, the stepper switch blocks being selectively actuated by commands from a remotely located central office controller. A continuity test circuit within each of the terminal boxes is responsive to commands from the central office controller for verifying that electrical contact is made between an associated one of the plurality X of distribution pairs of lines and a selected one of the plurality Y of drop pairs of lines. A control pair contention circuit within each of the terminal boxes allows a plurality of the terminal boxes forming a distribution network to be controlled by a single control pair of lines coupling all of the terminal boxes to the central office controller.

Abstract: An apparatus for verifying the central office billing translations from a remote location is disclosed. The system includes a processor with software which generates patterned telephone calls through a test set at the switch at a switching station to all working access codes. The billing information of these calls is then recorded. Once the recorded information is processed, the records which originated from the test set are identified by their assigned telephone number. These records are extracted and preferably recorded such that they can be automatically verified against an accurate routing and billing table for the specific site. The table is preferably stored in the test set.

Abstract: A site architecture for a trunked radio frequency communications system provides better fault tolerance capabilities than are available from architectures including redundant hardware. During normal system operations, a primary site controller performs most or all system control functions while signal processing functions are performed in a distributed manner by trunking cards associated with individual repeater channel receivers and transmitters. In the event the site controller fails, the trunking cards also begin performing trunking and other control functions. The trunking cards cease attempting to communicate with the failed site controller, and begin communicating directly with one another via a high speed backup serial link.

Abstract: An apparatus and method for testing voltage arresters and current shunting circuits within a telephone circuit protector are described. A typical protector tested by the apparatus and method includes two voltage arresters and two current limiting circuits. One set of a voltage arrester and a current limiting circuit are tested for voltage breakdown, continuity and ground faults by actuation of a single test operating switch. The other voltage arrester and current limiting circuit are then selected and tested by a single actuation of the test operating switch. Breakdown voltage, continuity, ground fault and low battery visual indicators are provided.

Abstract: A private branch exchange system connects a plurality of extension terminals to a digital network via a digital trunk circuit and a channel service unit. When a failure occurs between the digital trunk circuit and the digital network, a message generation instruction is generated. In response to the message generation instruction, a message generator in the digital trunk circuit generates a message. The generated message is transmitted to a specific extension terminal of the extension terminals.

Abstract: A computer interconnect coupler has channel transmitters and channel receivers and logic circuitry for the routing of messages from the channel receivers which are addressed to the channel transmitters. When a message is received by a channel receiver, the channel receiver stores the beginning portion of the message in a first-in-first-out buffer, and sends a route message request to central switch logic. If the destination transmitter or receiver is busy, the central logic places the message request on a destination queue and returns a signal to the requesting source transmitter to turn on a flow control signal which is transmitted back to the data processing device having originated the message. Any message addressed to this data processing device, however, is inserted into the flow control carrier with pauses both before and after the message, and provisions are also made to allow the data processing data to return an acknowledgment responsive to the incoming message.

Abstract: A telephone ringback apparatus includes a microprocessor-controlled communications device which is connectable with telephone equipment contained in a central office, such as a toll trunk facility, having the capability of identifying the number of a calling party. In response to the telephone user dialing a prescribed ringback access code, the apparatus signals the toll trunk facility causing it to transmit a message representative of the number of the telephone from which the user is calling. Upon receipt of this message the telephone number of the calling party is stored. A synthesized voice message is transmitted to the user instructing the user to hang-up. When the apparatus detects that the phone has been placed back on-hook, it proceeds to transmit dialing signals containing the previously stored number of the telephone, causing the calling party's telephone to ring.

Abstract: The invention relates to a distributed control-type electronic switching system which includes a first group of processors paired for act/standby redundancy, and a second group of master processors which are provided as single units. The first group of processors is connected to the speech-path switches and line and trunk circuits of a telephone switching system while the second processor group controls the various connections for the speech-path switches and the line and trunk circuits. Data communications between the first group of processors and the second group of processors is achieved on a distributed basis such that each processor of the first group designates a subset of the second group of processors as potential receivers, and conducts communications with the first non-busy processor of the subset.