Abstract: A measurement system and method for a telecommunication systems diagnoses problems within a communication line. The measurements are performed both non-intrusively and intrusively in an interactive manner, and evaluate the transmission quality of the communication line through to the subscriber's telephone set.

Abstract: An interconnection monitoring system for use with a multiple node wired network, the system comprising a plurality of transmitters, each located at a node of the network for transmitting a transmission from the node and a plurality of receivers, each located at a node of the network, for receiving a transmission at the node, the plurality of transmitters being operative to transmit along the network a signal bearing an identification code identifying the node from which a transmission takes place, the plurality of receivers being operative to receive transmissions from a plurality of nodes, bearing the identification codes and thus indicating the interconnection status of the nodes.

Abstract: In a method and system for recovering a faulty unit, a predetermined number of recovery periods, and the maximum number of times a recovery act is carried out during a recovery period, are defined. A faulty unit is taken out of operation, recovered (i.e. subjected to a procedure designed for remediating the fault, if possible), and brought back into operation if tests indicate that the unit is in condition (i.e., is not faulty). The recovered unit is monitored for the time of succeeding recovery periods and is re-recovered, if necessary, provided that the number of the recovery acts carried out during each recovery period does not exceed the maximum number predetermined for the respective period. As a result, bouncing of the unit back and forth in an uncontrolled manner, if the fault is of such a type that the recovery system cannot detect it on the basis of the tests carried out, is reduced and eventually curtailed.

Abstract: An apparatus and method for testing a telecommunication system, which runs telephony applications such as voice-mail, telephone banking systems, automated directory assistance, and multi-branched telephone customer service systems. The apparatus includes a test computer for scheduling and controlling the execution of test scripts, which include commands for generating network signaling, voice data, and digital data used to simulate transactions that typically take place on the telecommunication system; a database for storing the test scripts, test script input data, and test results; channels for running multiple test scripts in parallel; and, serial and voice ports for transmitting and receiving voice data and digital data to and from the telecommunication system.

Abstract: A test interface adapter allows a line-conditioning or test device, such as a direct access test unit (DATU), that is normally interfaced with a standard central office switch via a no-test trunk, to be coupled to and communicate with the respective ports of a test interface of a non-standard central office switch that is not equipped with a no test trunk, so that conditioning and/or testing of subscriber telephone lines served by such non-standard central office switch may be carried out. When so installed, the interface adapter of the present invention is operative to map signals at first interface ports, to which the non-standard central office switch is connected, to second interface ports to which the line conditioning/test device (e.g DATU) is connected, and vice versa.

Abstract: A method and connectivity evaluation system for testing trunk lines dedicated by a centralized telecommunications system to a customer switching system, such as a PBX, includes allowing the trunk-seizing capability of the telecommunications system to be remotely accessed from the premises of the customer switching system. The dedicated trunk lines can be sequentially isolated in response to the remote access of the trunk-seizing capability. Isolated trunk lines can be used to transmit test signals to opposite end equipment for evaluating characteristics of the signal. The test signals can be generated from either or both of the central office of the telecommunications system and the premises of the customer switching system, but in the preferred embodiment, all such transmissions are controlled from the customer switching system. In another embodiment, the transmissions are controlled from the central office.

Abstract: A power cross circuit detects a ring trip condition in order to switch a pair of switch relays to a protection circuit and to appropriate line driver circuitry to enable a talking condition for a telephone. The power cross circuit detects a rise in a DC current across a feed resistor connected to a ring bus and a ring line. The power cross circuit determines a difference in current passing across a first and second sense amplifier connected to respective ends of the feed resistor. The current difference is then converted to a voltage difference, and utilized by the power cross circuit to output a power cross condition when the current difference exceeds a predetermined value.

Abstract: A system and method for utilizing a common channel signaling network controlling a communications system to detect predetermined events and to execute a predetermined script upon detection of those events. This is accomplished using the common channel signaling network in conjunction with programmable and addressable monitors coupled to the common channel signaling links connected to the signaling transfer points (STPs). These monitors are programmed to trap and temporarily record predetermined data associated with specific events which it is desired to block or control. The monitors provide an output to a control processor having an SSP capability which is linked to the STPs. The monitors are programmed either through the common channel signaling network or through a monitor port connected to the control processor.

Abstract: A method and related system dynamically determines the location of a network outage in a telecommunications network. A plurality of alarm generating network equipments are located at spaced sites along the network. Alarms are generated upon the detection of problems with a signal passing through continuous signal trunks connected between the alarm generating network equipments. The alarm data from the alarm generating network equipments is connected at a single point. Network topology data is stored in a database, defining the relative locations of the alarm generating network equipments in the network and their respectively connected trunks. The alarmed equipment ports are correlated with respective connected alarmed trunks from data obtained in the database as well as collected alarm data. The alarmed trunks are analyzed for identifying the corresponding minimum number of alarm generating network equipments that exist between the alarmed trunks thereby defining effected inter-equipment trunks.

Abstract: An electronic private branch exchange includes a first fault detection portion, a first alternate control portion, a second fault detection portion, and a second alternate control portion. The first fault detection portion detects occurrence of a fault on a private line for connection to a remote electronic private branch exchange (EPBX). The first alternate control portion selects one of a plurality of integrated services digital network (ISDN) lines registered in advance after the first fault detection portion detects occurrence of the fault, thereby forming a first alternate communication path for alternate connection to the remote EPBX. The second fault detection portion detects occurrence of a fault on a first alternate line formed by the first alternate control portion.

Abstract: The portable line test telephone of the present invention consists of the switching means to operate different kinds of tests, the high voltage generating means to measure telephone capacity and insulation resistance, the dialing means to call and the call circuit means to talk with a subscriber or the called. Accordingly, line operator can make direct tests and examine telephone capacity, earth, line disconnection, line cross, insulation resistance with calling and talking with a subscriber.

Abstract: An improved telephone test device and a method of the same for an optical cable television which are capable of easily testing a telephone function of an optical cable television system by connecting to the subscriber's line of the optical cable television system without using an additional switch system, which includes the steps of a first step for initializing a database, selecting a predetermined bus, Cept interface boards-10, and a hardware, executing a menu, and judging the inputted menu; a second step for performing an extended common control board assembly loop-back test routine when the extended common control board assembly is selected in the first step for testing the extended common control board assembly loop-back; a third step for performing Cept interface boards-10 loop-back test routine when the loop-back is selected in the first step for performing the Cept interface boards-10 loop-back; a fourth step for performing a common test routine when the common test is selected in the first step; a fi

Abstract: A switching arrangement that can be connected in a communications channel that comprises a pair of lines between sets of terminal equipment, which comprises: (i) a series switch (1,2) for connection in each of the lines; (ii) a shunt switch for connection between the lines; and (iii) a control circuit (5) that can actuate the series switches (1,2) and can actuate the shunt switch on receipt of a signal sent along the channel: wherein the control circuit (5) can actuate the shunt switch and the series switches (1,2) on receipt of one or more signals but the shunt switch will remain closed over a different time period than that during which the series switches remain open, in order to allow different tests to be performed on the channel, and wherein one or more of the switches comprises a solid state switch.

Abstract: A metallic access test extender includes an office unit and a remote unit coupled to the office unit via a digital transmission system. A voltage controlled current source is included in the office unit and a voltage controlled voltage source in the remote unit. The voltage controlled current source is responsive to the voltage and current sensed at the remote unit load, and the voltage controlled voltage source is responsive to the voltage and current sensed at the input to the office unit. A shunt admittance which has a high impedance at DC and low frequencies is coupled to the office unit load.

Abstract: An integrated circuit is provided for a trunk interface which can test a trunk interface card. Switching circuitry couples tip and ring leads to signal detection circuitry which detects the typical ring and lead signal information. During testing, a test signal is generated which causes the detection circuitry to be coupled to sets of simulated ring and tip test signals which can test the functionality of the integrated circuit and the signal detection circuitry.

Abstract: A process for detecting link status in a computer network where the link and the load at the end of the link have a matched characteristic impedance. The data to be transmitted over the link is converted into a substantially continuous, random signal with a substantially known spectrum. This signal is transmitted over a link from a first end to the second or receiving end of the link. The first end of the link is analyzed for a reflection signal caused by a mismatch of the characteristic impedance of the link and the termination of the link. The link is identified as satisfactory if the reflection signal represents a substantial match between the characteristic impedance of the link and the characteristic impedance of the termination of the link. The link is identified as defective if the reflection signal represents a mismatch between the characteristic impedance of the link and the termination.

Abstract: Disclosed is a circuit which permits automatic switching between a main line and spare line at a subscriber's network interface device. A relay is provided between the two lines, which relay is triggered by a ringing signal on the line to be used.

Abstract: An SS7 Network Preventative Maintenance System for detecting potential SS7 and switched network troubles, automatically analyzing the troubles, providing alarm and corrective action to avoid major network events. Real time monitors on SS7 links at the STP provide information on exceeded link load, exceeded Message Signaling Unit (MSU) frequency and network management status/error conditions in a Stage 1 Process. The Stage 1 Process provides alarm information to a Stage 2 Process which controls all Stage 1 associated monitors for an STP pair. Stage 2 reacts to Stage 1 signals to generate alarm and corrective action information which is passed on to a Stage 3 Process. The Stage 3 Process controls all Stage 2 Processes in the operating company. Stage 3 reacts to Stage 2 output to detect potential or real accompanying network trouble and generates alarm and corrective action information and displays in response thereto. Stage 3 also alerts a Stage 4 process which is connected to all Stage 3 Processes in a region.

Abstract: A fault detection system for a broadband network having a central switch for switched telecommunications connections among subscribers each provided with subscriber interface equipment. The subscriber interface equipment has a received voice path and generates baseband signals for voice telephony which are carried at a carrier frequency on the broadband network. The fault detection system is provided with a tone generator for providing a constant, continuous pilot throughout the network. A pilot tone detector at the subscriber interface equipment detects the absence of pilot tone. The central switch is responsive to each pilot tone detection to recognize the absence of pilot tone at the corresponding subscriber location.

Abstract: A system for monitoring the performance of T1 digital transmission lines by incorporating a common unit interconnected to a plurality of network interface units as well as to a spare transmission line leading to a central office. The common unit is configured to interrogate any or all of the network interface units in order to obtain status information such transmission error rates, and to report such status information via the spare transmission line to the central office. By dedicating a common unit to oversee error detection and/or status reporting, communication between the central office and customer premises equipment need no longer be disrupted while transmission performance is being monitored.

Abstract: Non-intrusive performance monitoring of a DS0 channel between a customer premises interface and a D4 channel bank includes an augmentation of existing channel bank equipment and a digital services communication device terminating the DS0 link at the customer site. An auxiliary signalling and performance monitoring arrangement is remotely accessible by a non-resident control site, for example by way of an RS-232 port of a line interface unit of the channel bank, thereby enabling the control site to perform prescribed network supervisory tasks with respect to one or more selected DS0 links, including provisioning of their associated loop equipment and performance monitoring of each DS0 loop. Office channel unit data port and line interface components of the channel bank are modified to provide bidirectional signalling capability via the receive segment of the channel bank's internal communications link.

Abstract: Apparatus and method for testing lines. The apparatus is particularly useful for testing lines in a switched network, such as might be used to electronically route telephone and computer data lines to various offices in an office building. The apparatus includes an AC test source and a DC measurement device located at a near end switch. A DC transform circuit is located at a far end switch. According to the test method, an AC test signal is injected onto a line under test at the near end. At the far end, the received signal is converted to DC, which is sent to the near end. Line attenuation, and hence fault conditions, are detected by comparing the DC signal to the transmitted AC signal. Techniques to increase the signal to noise ratio of the DC signal are also disclosed.

Abstract: An interface scanning circuit includes a current source at the input to a multiplexer. The current source includes a transistor disposed between two resistors, the second one of which limits reverse current. Also provided are an attenuating network including two resistors, and a low pass filter capacitor associated with the attenuating network.

Abstract: A test interface adapter allows a line-conditioning or test device, such as a direct access test unit (DATU), that is normally interfaced with a standard central office switch via a no-test trunk, to be coupled to and communicate with the respective ports of a test interface of a non-standard central office switch that is not equipped with a no test trunk, so that conditioning and/or testing of subscriber telephone lines served by such non-standard central office switch may be carried out. When so installed, the interface adapter of the present invention is operative to map signals at first interface ports, to which the non-standard central office switch is connected, to second interface ports to which the line conditioning/test device (e.g DATU) is connected, and vice versa.

Abstract: The possibility of corrupting digital data traffic carried by a data line (powered or unpowered), by the connection of a telephone test set to the data line is effectively prevented by augmenting the telephone test set with a mechanism that prevents the test set from asserting an OFF-HOOK condition on the line, unless it has been determined that each of two conditions are satisfied. These conditions are: 1- that no digital data traffic is being carried by the line; and 2- that the electrical voltage condition of the line satisfies a prescribed minimum voltage level criterion. If either of these conditions is not satisfied, a switch circuit installed in the test set's connection path to the line is maintained in a default, open condition, so that it is effectively impossible for the line to be presented with an OFF-HOOK condition through operation of the test set. This default condition remains in effect until both criterion are fulfilled.

Abstract: A processor-controlled integrated telephone line measurement and conditioning apparatus installable at a remote site provides a multiplicity of measurement and conditioning functions that are selectively executable in response to commands issued from a supervisory command site. The dual measurement and conditioning capabilities of the architecture of the present invention impart both remote measurement unit (RMU) functionality and metallic access unit (MAU) functionality that may be individually accessed and controlled. The RMU operates primarily as a test head that performs mechanized loop testing (MLT) tasks, while the MAU is operative to impart prescribed electrical conditions to a specified line circuit. When controllably accessed to operate as an RMU, the present invention responds to instructions from a command site (loop maintenance operations systems) and performs single-line demand tests on a line provided by a pair gain system.

Abstract: The disclosed facility type determination technique ascertains whether or not a facility connection is solely digital. In the disclosed embodiments, this information is used to establish the rate at which data is coupled through the facility connection. More specifically, a predetermined test signal including a pseudorandom sequence of digital signals is transmitted through the facility or combination of facilities connecting a data source to a data destination after the connection between the source and destination is established. The received test signal is examined at the destination and the examination results are used to determine the rate at which data is subsequently transmitted between the data source and data destination. Advantageously, this technique does not restrict network facility management and can be employed in a variety of data communication applications.

Abstract: A transmission system provides a stand-by line switching facility. The transmission system includes a plurality of working line side processing equipments and a stand-by line side processing equipment to replace one of the working line side processing equipments if a fault occurs therein. The transmission system has a first unit and second unit disposed for each working line side processing equipment. The first unit issues, upon receipt of a line switching command, a single line switching control signal. The second units commonly receive the single line switching control signal and respective line switching is performed between the faulty working line and the stand-by line simultaneously.

Abstract: An inductive amplifier for identifying and tracing wires includes a comb filter for nulling out 60 Hz. power line "hum", as well as harmonics of 60 Hz. The inductive amplifier includes a probe for sensing an input signal. The comb filter includes a time delay circuit for providing a delayed output signal that is delayed by 16.67 milliseconds, or one 60 Hz. cycle, compared to the input signal. The comb filter also includes an inverter circuit for providing an inverted output signal that is 180 degrees out of phase with the input signal. The comb filter further includes a summer for summing together the delayed output signal and the inverted output signal to null out harmonic components of 60 Hz. while passing other signals to the output of the comb filter. The nulling method may also use digital processing techniques rather than discrete circuit components.

Abstract: An inductive amplifier for identifying and tracing wires includes an automatic gain control feature for sensing the connection of butt set leads to the inductive amplifier and reducing the gain of the inductive amplifier in such instances to reduce the likelihood of instability or oscillations. The inductive amplifier includes a probe for sensing an input signal which is filtered and amplified for driving either an internal speaker or a speaker in the earpiece of an external butt set. The inductive amplifier includes circuitry for sensing that the leads of the butt set have been connected to the inductive amplifier, and for reducing the gain of the inductive amplifier by a factor of ten under such circumstances.

Abstract: An SS7 Network Preventative Maintenance System for detecting potential SS7 and switched network troubles, automatically analyzing the troubles, providing alarm and corrective action to avoid major network events. Real time monitors on SS7 links at the STP provide information on exceeded link load, exceeded Message Signaling Unit (MSU) frequency and network management status/error conditions in a Stage 1 Process. The Stage 1 Process provides alarm information to a Stage 2 Process which controls all Stage 1 associated monitors for an STP pair. Stage 2 reacts to Stage 1 signals to generate alarm and corrective action information which is passed on to a Stage 3 Process. The Stage 3 Process controls all Stage 2 Processes in the operating company. Stage 3 reacts to Stage 2 output to detect potential or real accompanying network trouble and generates alarm and corrective action information and displays in response thereto. Stage 3 also alerts a Stage 4 process which is connected to all Stage 3 Processes in a region.

Abstract: A self diagnostic test routine resident in firmware in a remote, programmable device for testing telephone lines diagnostically examines the operational capability of each of a plurality of prescribed signal processing functions contained within the test device, on a selected one of a `loop` (effectively continuous) basis, `automatically`--at a less than continuous but still meaningfully periodic rate, or `on-demand`--at any time requested by the user. In addition, a running log is maintained of the results of each diagnostic test, and the results of each diagnostic test are compared with a set of thresholds associated with respectively different standards of performance of the test device. As a result of this comparison, the performance capability or status of the device is classified into one of three categories: PASS, MARGINAL, or FAIL, and communicated to system maintenance personnel.

Abstract: A microprocessor-controlled voltage source selectively provides to a telephone line either a DC or an AC voltage, prescribed characteristics of which are programmably adjustable, enabling test equipment to controllably condition and test the line with essentially any desired line conditioning voltage or signal waveform. A digital-to-analog converter (DAC) provides an output voltage having an amplitude that is digitally programmable. This output voltage is available to be applied either directly or through controlled amplifier circuitry to the line. In order to generate an AC signal having both an adjustable amplitude and waveform characteristic, the output of the DAC sets the amplitude for a combination of signals from a plurality of squarewave generators having programmable frequency characteristics. The output of the combining unit is coupled to a switched capacitor filter which filters the controllably-interrupted, digitally-controllable output voltage, (e.g.

Abstract: An automatic circuit back-up system is adapted to a data communication system including a private communication line for data communication and a back-up communication circuit for providing a back-up for the private communication circuit. The automatic circuit back-up system includes a periodic message transmitting circuit for transmitting a periodic message at a predetermined regular period to a distant office through the back-up communication circuit, and a monitoring circuit for monitoring whether the periodic message transmitted from the distant office via the back-up communication circuit is received at the predetermined regular period.

Abstract: An administrative computer and testing apparatus device is provided. The administrative computer is coupled to the testing apparatus so that the test data can be correlated with administrative information such as the location of the equipment tested. The testing apparatus can be configured as a slice for insertion between upper and lower portions of the administrative computer. The administrative computer can control the testing apparatus to provide testing in accordance with predefined test procedures. The administrative computer is user-programmable to permit user-defined test procedures to be established. Test data, e.g. test data correlated with the location information, can be communicated to a remote computer for further processing or analysis. Communication can be implemented through a modem, which can be a land-line modem or an RF or other wireless modem.

Abstract: A connector unit (21) for automatically terminating a digital data services (DDS) line whenever a mating modular plug (30) is not inserted into the connector. The connector utilizes a switchable DDS jack (25) that mates with the modular plug (30) for connecting a data-transmit line and a data-receive line of a DDS network (41) to a customer's equipment (45). The connector unit has a maintenance termination circuit (40) with terminating impedances (r, r1, C and C1) and diodes (D and D1). When the plug and jack are not engaged, the maintenance termination circuit is connected to the data-transmit and data-receive lines via the normally closed jack contacts (33 and 34). As the plug and jack are engaged, the plug abuts against and, as movement continues, increasingly opens the jack contacts, causing the maintenance termination circuit to be disconnected from the customer's equipment and to be connected to the DDS network.

Abstract: An SS7 Network Preventative Maintenance System for detecting potential SS7 and switched network troubles, automatically analyzing the troubles, providing alarm and corrective action to avoid major network events. Real time monitors on SS7 links at the STP provide information on exceeded link load, exceeded Message Signaling Unit (MSU) frequency and network management status/error conditions in a Stage 1 Process. The Stage 1 Process provides alarm information to a Stage 2 Process which controls all Stage 1 associated monitors for an STP pair. Stage 2 reacts to Stage 1 signals to generate alarm and corrective action information which is passed on to a Stage 3 Process. The Stage 3 Process controls all Stage 2 Processes in the operating company. Stage 3 reacts to Stage 2 output to detect potential or real accompanying network trouble and generates alarm and corrective action information and displays in response thereto. Stage 3 also alerts a Stage 4 process which is connected to all Stage 3 Processes in a region.

Abstract: Non-intrusive performance monitoring of a DS0 channel between a customer premises interface and a D4 channel bank includes an augmentation of existing channel bank equipment and a digital services communication device terminating the DS0 link at the customer site. An auxiliary signalling and performance monitoring arrangement is remotely accessible by a non-resident control site, thereby enabling the control site to perform prescribed network supervisory tasks with respect to one or more selected DS0 links. Office channel unit data port and line interface components of the channel bank are modified to provide bidirectional signalling capability via the receive segment of the channel bank's internal communications link.

Abstract: A remote measurement unit for testing and conditioning one or more telephone lines includes multiple electronically erasable flash memory banks, which contain respective versions of the operating system employed by the test unit's micro-controller. An operating system modification routine employed by the host processor of a remote site allows the functionality of the remote test unit to be selectively modified by electronically installing an upgraded or downgraded version of the operating system, or by electronically selectively activating or deactivating one or more operational features of the currently active operating system. A reset routine ensures that the operating system modification mechanism will only boot up the `correct` one of the two quasi-redundant systems available to the RMU's microcontroller after a system modification has been performed.

Abstract: For obtaining a longitudinal balance of a pair of relatively long wires, a sinusoidal stimulus signal is generated by processing digital reference signals and is applied to the pair in at least two different connection profiles. Voltages at each wire are measured in each connection profile and are combined with the digital reference signals to derive drive representative values and metallic representative values of the pair of the long wire. The longitudinal balance is calculated from these representative values. The invention requires no highly balanced circuit to provide highly accurate measurements. The measurement inaccuracies and inherent unbalance of the measuring circuitry are eliminated by the use of at least two connection profiles and signal processing.

Abstract: An operating system is provided for an analog switching machine having switch fabric formed by multiple line and trunk link networks having interconnected switch stages with each switch stage having multiple grid connections and makes post-connection continuity checks. Error messages are generated for connection faults and sent to a monitor and analyzer computer. The error messages are automatically processed to identify the root causes of connection faults, i.e. to detect open and stuck crosspoints, faulty interstage links and faulty pulse path devices. The analyzer computer further generates command signals that provide for removal of faulty crosspoints and other failed elements from analog switching machine operation.

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: In a switched telecommunications network having multiple SPC switches connected to one another by trunks and connected to signal transfer points (STPs) by common channel signal (CCS) links, dual port protocol analyzer and control (DIAC) devices are situated at two STPs which are connected together by control and data communication links. One input of one of the DIAC device is connected through a first CCS link to a switch to be monitored and the second input of the DIAC device is connected via the data communication link to the second STP and from the second STP via a CCS link to the switch to be monitored to provide at the DIAC device a simultaneous presentation of CCS signals appearing at the terminations of the CCS links at the switch to be monitored.

Abstract: An "intelligent" maintenance termination unit (MTU) that can be installed at or near the demarcation point between the telecommunications network and Customer Premises Equipment (CPE), includes a program controlled processor arranged to perform numerous testing and evaluation functions on (1) the CPE and the drop portion of the telecommunications circuit located on the customer side of the MTU, as well as (2) the line portion of the telecommunications circuit on the network side of the MTU. Testing may be initiated in response to actuation of a pushbutton switch or other initiation means by the customer. Specific tests are then performed in response to receipt of signal sequences (such as Touch-Tone signals) received from a technician at a remote test center.

Abstract: A testing system for digital transmission lines with a metallic loopback and direct current bypass for use with regenerative repeaters. The Bell telephone network typically includes transmit and receive lines interconnected to a central office. Regenerative repeaters positioned along the lines detect signals and regenerate new signals. The present invention includes a controller, loopback line, and bypass. The loopback line interconnects the transmit and receive lines upon receiving a test activation signal from the controller. The bypass allows direct current to pass through to the rest of the line during a test. Accordingly, when a test of the telephone lines is to be performed, lines will allow the test signal to loop back to the source of origin, but will block the loopback of DC power signals. Moreover, DC power is supplied to the rest of the transmission line, in the same manner as when the testing procedure is not occurring.

Abstract: A public modular telephone management system. By using several units and systems, as well as ancillary elements for managing public modular telephones, it is possible to provide the public modular telephones with means of making payment for the service by using several types of cards such as: credit, prepayment, telephone subscriber or multiservice cards.

Abstract: A plurality of disparate communication network systems communicate with each other through the use of different physical media protocols. Each of the systems has at least one input and one output. A message routing system couples a transmitter at any one system input to a receiver at any other system output using a message format that is structure independent of the location of the receiver in the system. Each receiver/transmitter device coupled to any one system input has a unique, fixed and unchangeable identification code regardless of the communication network system to which it is connected. To couple a message from any one receiver/transmitter device to a second receiver/transmitter device at an unknown location within the communication network system, a message format is transmitted from the sending location containing the fixed, unique identification code of the receiving station.

Abstract: A pair of unused telephone lines are connected together at a telephone office main frame by a device which is removably plugged in the main frame to connect a diode between said lines. At a point remote from the central office a testing circuit, which comprises a battery in series with a tone emitter, is releasably connected across the lines first with one polarity with respect to the lines, and then with the opposite polarity. If a tone is emitted for only one connection but not the other, the lines should be in working order.

Abstract: Apparatus for testing the performance of a communication line that carries customer data between two modems, including a programmable processor (for example, a digital signal processor) in each modem that either performs modulation or demodulation of customer data or tests the line, and a controller (for example, a programmable host processor) that switches the programmable signal processor selectively between processing customer data and line testing. The communication line carries both customer data and network control commands that include a test command for initiating testing, and each host processor responds to the test command by switching the signal processor to the test mode. There are a plurality of modems forming a data network and a central network control system connected to the network for providing the test command. The test command names two of the modems to participate in the testing and the controller identifies whether a given modem is one of the participants.

Abstract: A circuit and method for enabling the automatic testing of trunks leading to automatic call distributors from a remote testing location is disclosed. In accordance with the invention, when the remote testing location wishes to test a trunk leading to an automatic call distributor, tones are generated which enable the remote testing location to be connected to a test line of the automatic call distributor rather than to an operator position.