Abstract: A system and method of telephony resource management and security for monitoring and/or controlling incoming and outgoing calls between an enterprise's end-user stations and a public circuit-switched network and/or a public packet-switched network. A security policy is made up of one or more rules designating at least one action to be performed based on at least one attribute of the incoming or outgoing call. Calls are detected and sensed on the line, trunk and/or cabling, and analyzed to determine attributes associated with each call. Actions are performed based upon the determined attributes, in accordance with the security policy rules.

Abstract: An example disclosed method comprises receiving a combined signal at a customer premises, the combined signal including a first signal associated with a first frequency range and a second signal associated with a second frequency range larger than the first frequency range, monitoring for power outages at the customer premises, and when no power outage at the customer premises is detected, switching the second signal for distribution at the customer premises using a wireline distribution system integrated in the customer premises, and switching the first signal for distribution at the customer premises using a wireless distribution system and without using the wireline distribution system.

Abstract: One embodiment is a method for performing 2-wire line imbalance measurements. The method comprises receiving a probe signal and based on the probe signal, determining one of more of: an estimated transverse conversion loss (TCL) coupling transfer function and an estimated transverse conversion transfer loss (TCTL) coupling transfer function.

Abstract: A FDR SELT measurement is made in a stop band of a DSL band plan, using a PSD allowed by the PSD mask. Further measurements may also be made in an adjacent pass band and further bands, and the results combined to create a wide-band measurement result. When transformed into the time domain (e.g. by inverse Fourier transform to produce the line impulse response) greater resolution in time (and hence greater spatial resolution) is achieved. In order to compensate for AGC calibration errors measurements using different AGC steps may be scaled to fit smoothly to each other. If measurements overlap, measurement results in the region of overlap may be combined in various ways to limit the influence of noise and to create a smooth transition from one measurement to the next.

Abstract: Monitoring criteria is received that corresponds to a usage quantity for a plurality of services. Each of the plurality of services is provided over ones of a plurality of different communication systems. Actual service usage information is received for the plurality of services. The actual service usage information and the monitoring criteria are compared. An electronic notification message is sent when the monitoring criteria for one or more of the plurality of services is satisfied.

Abstract: A call control system comprising a control module, a translations database and a switching fabric are connected to a trunk group between a remote terminal and its controlling local switching office. The call control system monitors control signals from the switching office on the trunk. In the event of loss of control signals, the call control system intercepts requests for service, etc. from a calling telephone connected to the remote terminal and performs a look up in the translation database. If the call can be completed without the controlling switching office the call is looped back to the remote terminal. The translation database is maintained by a remote terminal OA&M interface that receives change orders from the local exchange carrier. The remote terminal OA&M interface forwards relevant changes to the call control system's translation database.

Abstract: A system and method for monitoring the state of a structure over a network. The system and method provides for providing the status of a monitoring device to a status file. The status file is accessible over the Internet by computer so that a party can first determine the status of the device. The system operates over normal PSTN's, over cable systems, over wireless networks and over the Internet.

Abstract: A method includes selecting a first set of digital subscriber lines (DSLs) supported by a digital subscriber line access multiplexor (DSLAM). The DSLs of the first set exhibit reduced performance based on historical performance data. The method includes sending a request to the DSLAM for a first performance parameter for each of the DSLs of the first set. The method includes receiving the first performance parameters. The method includes removing DSLs from the first set that have suitable performance based on the first performance parameters to create a second set of DSLs. The method includes selecting a line profile to apply to the second set of DSLs. The method also includes sending a second request to the DSLAM to apply the line profile to the DSLs of the second set and then to determine a second performance parameter for each of the DSLs of the second set.

Abstract: A method, system, and program for telephony based remote location monitoring are provided. A telephone network receives the caller request to listen only to a remote location telephony device. The telephone network allocates a listen only channel between the caller telephony device and the remote location telephony device. The telephone network activates a microphone at the remote location telephony device via the listen only channel. Then, audio detected at the microphone is streamed via the listen only channel to the caller telephony device, such that the telephone network enables a caller to monitor a remote location through the remote location telephony device with minimized allocation of telephone network resources.

Abstract: Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol and users. The operational data collected from the system can include performance-characterizing operational data that typically is available in the OSL system via element-management-system protocols. Generated estimates and/or approximations can be used in evaluating system performance and directly or indirectly dictating/requiring changes or recommending improvements in operation by transmitters and/or other parts of the indication system. Data and/or other information may be collected using internal means or using system elements and components via e-mail and/or other extra means. The likelihood of the models accuracy can be based on various data, information and/or indicators of system performance, such as observed normal operational data, test data and/or prompted operational data that shows operating performance based on stimulation signals.

Abstract: A method run in a gateway for detecting a communication link between a called telephone and a telephone switch is provided. The method firstly detects if a ringer equivalency number (REN) is equal to zero. If the REN equals to 0, the method further determines if each discharge curve of a positive wire and a negative wire of the called telephone complies with a corresponding standard discharge curve, so as to determine if the communication link between the called telephone and the telephone switch has been established.

Abstract: An autodiscovery system provides content credentials to customer premise equipment through an event-driven architecture. The autodiscovery system includes several modules for implementing the event-driven architecture, such as an autodiscovery front-end module, an autodiscovery back-end module, and a broadcast activation module. The autodiscovery system may also include a subscriber database that stores subscriber records that identify subscribers associated with a level of service, a customer premise equipment identifier, or both. The modules of the autodiscovery system may also communicate with a conditional access system that communicates the content credentials to a data carousel. When the content credentials are made available on the data carousel, the autodiscovery front-end module may notify the customer premise equipment that the content credentials are ready for retrieval from the data carousel.

Abstract: Configuration or otherwise controlling parameters of a Digital Subscriber Line (DSL) system related to power, band usage and margin is based on collected operational data. Operational data are collected from at least one DSL system operating under a known configuration and/or a profile. A target profile is selected based on binder-level information. The collected operational data is analyzed and conditions for changing the DSL system configuration to the target profile are evaluated, including any applicable transition rules pertaining to changing profiles. If the conditions hold, then the DSL system is instructed to operate with the target profile. Binder-level information can include deployment point information, topology information, and/or crosstalk coupling information. The controlled parameters may have values that are chosen using one or more spectrum balancing methods. Such spectrum balancing methods may be executed infrequently, and may make use of all binder-level information that is available.

Abstract: A method for controlling a ringing signal includes generating a ringing signal on a subscriber line, detecting a condition indicative of the subscriber line going off-hook and reducing an amplitude of the ringing signal responsive to detecting the condition. A line card includes a subscriber line interface circuit operable to generate a ringing signal on a subscriber line and a subscriber line audio-processing circuit operable to detect a condition indicative of the subscriber line going off-hook and reducing an amplitude of the ringing signal responsive to detecting the condition.

Abstract: A method for reducing noise is in a subscriber line interface circuit of a phone includes detecting a work state of the phone, and reading a voltage on hook on the tip wire when the phone is in the on hook state. Voltages of an off hook state on the tip wire and a voltage off hook state on the ring wire are read when the phone is in the off hook state, and calculation of a public voltage based on the voltages in the register, and loading the public voltage on the ring wire are done. The public voltage on the ring wire are converted into oscillatory voltages on the ring wire in symmetric wave forms having phases opposite to those on the tip wire, when the phone is in the pulse dialing state.

Abstract: A system includes a hybrid fiber coax (HFC) network having network elements operable for communicating telephony, data, and video signals with customer-premises equipment (CPE) of subscribers. The system includes a manager for monitoring status and the configuration including the assigned capacity of the network elements and for generating alarm data indicative of improper status or configuration of the network elements. The system includes a database for storing data indicative of the status and the configuration of the network elements and for storing data indicative of physical and logical connections between the network elements and the CPE. The system includes an alarm visualization tool operable with the manager and the database for generating visual displays of the status and configuration including the assigned capacity of the network elements overlaid with the alarm data and the stored data indicative of the physical and logical connections between the network elements and the CPE.

Abstract: The embodiments of the present invention disclose a spectrum optimization method and device and digital subscriber line system, the method comprising: calculating according to acquired information of each of respective subcarriers on the DSL line to be optimized to obtain optimized transmission power of a subcarrier to be optimized in a DSL line to be optimized; calculating a transmission rate of the DSL line to be optimized according to the optimized transmission power; and comparing the transmission rate with a target rate of the DSL line to be optimized, and if the transmission rate is less than the target rate, updating the information of an optimized subcarrier, and performing a recalculation.

Abstract: Methods, systems, and computer program products for performing a trace of a communications transaction using a dynamically generated endpoint identifier list are disclosed. According to one method, a first endpoint identifier for identifying a communications endpoint is received. A list including the first endpoint identifier is created. A signaling message including the first endpoint identifier may be searched for in the list. A parameter from the signaling message having the first endpoint identifier may be extracted that is distinct from the endpoint identifier. Further, the method may include searching for signaling messages having the extracted parameter. The method may include adding to the list any endpoint identifiers found in the search for signaling messages having the extracted parameter. The method may include searching for signaling messages having any of the endpoint identifiers in the list and thereby tracing a communications transaction involving endpoints in the endpoint identifier list.

Abstract: A mobile communication terminal for providing a content and its method are disclosed. The mobile communication terminal for providing content includes a transceiver for receiving a content from a server; a display unit for displaying the content received from the transceiver on a pre-set region; and a controller for controlling the transceiver to receive the displayed content and controlling the display unit.

Abstract: The embodiments relate to methods and apparatuses for tracking data calls placed to or from a terminal of a call service subscriber using of an advanced intelligent network in real time in a communications network. A SDS query to an SCP in communication with a database is made when a specific trigger for a call assigned to a subscriber is detected. Call information and subscriber number data is extracted from the SDS query and saved in the database.

Abstract: A system and method for establishing a telephone call between a calling party telephone and a called party telephone over a wired network. A telephone number associated with the called party telephone is monitored using a telephone status monitor to obtain a status of the called party telephone. The status of the called party telephone is entered in a called party telephone status file that is accessible to a calling party processor over the wired network. The calling party processor dials the telephone number of the called party telephone when an on-hook status is detected by the calling party processor so as to establish a telephone call between the calling party telephone and the called party telephone over the wired network.

Abstract: Example methods and system to validate proper network connections between a digital subscriber line (DSL) access multiplexer (DSLAM) and the subscriber loop to a customer location are disclosed. A disclosed example device includes first and second nodes to electrically couple the device to a port of a DSLAM and to a first end of a communication circuit, the communication circuit to facilitate electrical coupling of the port of the DSLAM to a central office (CO) switch at a second end of the communication circuit, and a signature circuit electrically coupled between the first and second nodes to generate a signature signal in response to a test signal injected onto the communication circuit at a second end of the communication circuit, the signature signal having a magnitude substantially proportional to the test signal.

Abstract: Methods, systems, and products are disclosed for selecting cable pairs. Data is received describing existing communications equipment being used in connection with a service at a customer service location. An assignment is retrieved for a cable pair associated with the customer service location. Replacement cable pairs are requested to replace the assigned cable pair. At least one alternate cable pair is received that is available to provide the service at the customer service location.

Abstract: Systems and methods for generating performance metrics to monitor and/or enhance the performance of telephone-intensive personnel are disclosed. The method generally includes detecting voice activity on a receive and/or a transmit channel in a communications system, outputting voicing decision outputs based on the detecting, storing the voicing decision outputs over a period of time to memory, and generating voice activity performance metrics based on the voicing decision output stored in the memory. The generating may include generating a running average ratio of duration of voice activity on the transmit channel to duration of voice activity on the receive channel (talk-listen ratio) over a certain period of time for one or more agents. The talk-listen ratio may be compared to a target ratio.

Abstract: A wiring verification system is disclosed for testing the correct pairing of a plurality of subscriber lines between an existing line termination system and a replacement line termination system to assist in the transfer of the subscriber line terminations from the existing line termination system to the replacement system. The wiring verification system comprising a controller and two testheads, one of which places test calls from the line under test to a designated test line that is terminated by the second testhead. The electrical qualities of the wye splices between lines associated with new line termination system and those of the existing line termination system are analyzed for correctness and possible hazardous conditions. The directory number of the line under test can be verified by decoding the calling line ID. Automated test strategies provide details related to which splices require attention and suggestions for remediation.

Abstract: A Call Server in a network is able to monitor an offered rate of incoming calls per Access Gateway (AGW). A calculated GlobalLeakRate can be distributed between the AGWs in proportion to the traffic rate they offer. A leak rate calculation method is used to calculate the GlobalLeakRate control parameter of the ETSI NR restrictor at an overloaded Control Server The leak rate calculation is based on the POTS call rejection rate. In one particular embodiment of the present invention, the calculation is based on bringing the call reject rate close to a configurable low target reject level. An MGC is able to identify the end of an overload event with a greater degree of confidence and an AGW is able respond appropriately if the AGW is prematurely instructed to stop the control.

Abstract: A line measurement method is provided. The method includes obtaining data of relation between a line length and an insertion loss phase radian, and obtaining data of relation between the line length and a loop attenuation parameter value; obtaining four length values from the data of relation between the line length and the insertion loss phase radian, and defining a length range to obtain the first and the second length range; and determining the boundary of the second length range close to a midpoint of the first length range, using a line length value corresponding to the boundary close to the midpoint as a measured line length, and using a line diameter corresponding to the line length value as a measured line diameter.

Abstract: Monitoring criteria is received that corresponds to a usage quantity for a plurality of services. Each of the plurality of services is provided over ones of a plurality of different communication systems. Actual service usage information is received for the plurality of services. The actual service usage information and the monitoring criteria are compared. An electronic notification message is sent when the monitoring criteria for one or more of the plurality of services is satisfied.

Abstract: A system, method, and transceiver unit for determining one or more properties of a digital subscriber line (DSL) utilizing a time-variable finite impulse response (FIR) filter. The transceiver unit sends a loop test signal to the line and calculates an impulse response of a reflection of the loop test signal from the line. The calculated impulse response is filtered utilizing the time-variable FIR filter and properties of the line are determined. Characteristics of the FIR filter may be controlled by a set of parameters that vary as a function of time according to a predetermined formula. As a result, the FIR filter provides both high time resolution of closely separated pulses and amplification of far-end pulse reflections.

Abstract: While determining a leak resistance of a subscriber connection line provided, for example, with two wires in a communication network, a capacitor connected between two said wires is discharged prior to measuring leakage currents. For this purpose, prior to be connected to a high resistance of the other wire, the measurable wire and the other mentioned wire are supplied with a constantly falling and increasing voltage. For that, the final value of said tensions is determined in such a way that, when the connection to the high resistance of the other wire is produced, the voltage of said wire is equal to 0 volt. The leakage current is measured only when the discharge process is over, thereby making it possible to avoid an incorrect measurement caused by a current coming from the capacitor.

Abstract: A method and arrangement for estimating line insertion loss of a customer transmission line at a frequency (f1) or a plurality of frequencies. Values of line insertion loss for at least two reference transmission lines are pre-measured at each frequency and stored in a memory. A calibration quantity representing an amplitude of a far-end Time Domain Reflectometer (TDR) reflection is also measured for each of the reference transmission lines. The pre-measured line insertion loss of each reference transmission line is then calibrated by the calibration quantities of the reference transmission lines. The calibration quantity for the customer transmission line is then measured, and an estimate of the line insertion loss at each frequency for the customer transmission line is generated based on the calibrated line insertion losses of the reference transmission lines and the measured calibration quantity of the customer transmission line.

Abstract: A method for training line drivers in a communication system; each driver coupled with at least one communication line configured for communicating with subscriber equipment using at least one tone-set; includes the steps of: (a) selecting a test driver; (b) selecting a test line coupled with the test driver; (c) establishing synchrony with subscriber equipment on the test line; (d) applying a test signal to the test line using a selected tone-set; (e) determining noise on the test line; (f) evaluating whether noise on the test line plus a noise margin is within a predetermined range; (g) when noise is acceptable, designating the selected tone-set for operational employment; (h) repeating steps (b)-(g) until sufficient lines are evaluated for the test driver; and (i) repeating steps (a)-(h) until sufficient drivers are evaluated.

Abstract: A method and device for recording call failure information in a data transmission system is provided. The failure logs generated in response to a failure event include a failure type and a first timestamp. A log record is created for a first failure log based on the failure type, and storied in a log record storage. Whenever a further failure log is generated in response to the same failure event, the further failure log includes said failure type and a current timestamp, so that it will receive the same identifier. The log record is updated to document the current timestamp.

Abstract: A system and method of telephony resource management and security for monitoring and/or controlling and logging access between an enterprise's end-user stations and their respective circuits into the public switched telephone network (PSTN). One or more rules are defined which specify actions to be taken based upon at least one attribute of a call. Calls are detected and sensed to determine attributes associated with each call. Actions are then performed on selected calls based upon their attributes in accordance with the defined rules.

Abstract: Controlling use of a telephone line includes receiving a specification from a first entity that defines one or more supervisory controls on use of a controlled telephone line by a second entity. The supervisory controls specify people with whom the second entity may or may not communicate over the controlled telephone line, and times at which the second entity may or may not communicate over the controlled telephone line. An indication of desired communications between the second entity and a third entity at a particular time over the controlled telephone line is received. A determination is made as to whether the desired communications are consistent with the specified supervisory controls. The desired communications are controlled when the desired communications are not consistent with the specified supervisory controls. In addition, the supervisory controls enable the first entity to interrupt existing calls over the controlled telephone line.

Abstract: A method of performing maintenance on a network access server having associated channels carrying incoming digital or analog traffic determines whether maintenance is needed on a network access server and then communicating a busy condition of any unused associated channel from the network access server to the service request switch. Used channels are monitored for existing calls and when the used channel becomes substantially unused as indicated by defined digital and analog signaling protocol a busy condition is communicated from the network access server to the service request switch. An unused channel may be determined by usage falling below a predetermined threshold. Any remaining, existing calls are migrated to other network access servers. A signal is then sent to indicate that maintenance on the network access server can be performed and new requests arriving during a busy condition of the network access server are routed to another network access server.

Abstract: A system for presenting telephone state information includes a presence server 10; a presence client end 20 and a presence contact end 30 which are respectively connected with the presence server 10 and communicate with each other through the presence server 10; a user telephone line monitoring device 40, used for monitoring the state of the user telephone line 50, and sending the monitored state to the presence client end 20. Wherein, the presence contact end 30 is used for displaying presence information of a corresponding telephone state of the presence client end 20 it subscribed. The present invention also provides a method for presenting telephone state information. Through the invention, a client can inform his/her telephone state information to the contacts in time. The system and method do not depend on special telephone switch, and have a low cost, can be used in any area.

Abstract: A trouble ticket handling system is provided. The system typically includes a login logic, a monitoring device, and a user interface logic. The login logic typically operates to log a user into several trouble ticket systems. The monitoring device typically polls the trouble ticket systems for open trouble tickets. The user interface logic enables the user to automatically load a proper trouble ticket from any of the open trouble tickets in the trouble ticket systems. Methods and other systems are also provided.

Abstract: Data generated at a telecommunications network switching node is selectively delivered to one or more data receiving device (e.g., data “collection box”) connected to the network, and command and control signaling is transmitted from the data receiving device to the switching node. This bi-directional communication is carried out in a manner compatible with voice grade lines. In an exemplary application, call identifying information, referred to in the TIA/EIA Standard as CDC (Call Data Channel) Messages, is delivered from an Intercept Access Point (IAP) switch that provides telephone service to a subject of an authorized surveillance order, to a law enforcement data collection box, utilizing Frequency Shift Keying (FSK) signals. Control signals are sent from the data collection box to the IAP switch utilizing Dual Tone Multi-Frequency (DTMF) signaling.

Abstract: Controlling use of a telephone line includes receiving a specification from a first entity that defines one or more supervisory controls on use of a controlled telephone line by a second entity. The supervisory controls specify people with whom the second entity may or may not communicate over the controlled telephone line, and times at which the second entity may or may not communicate over the controlled telephone line. An indication of desired communications between the second entity and a third entity at a particular time over the controlled telephone line is received. A determination is made as to whether the desired communications are consistent with the specified supervisory controls. The desired communications are controlled when the desired communications are not consistent with the specified supervisory controls. In addition, the supervisory controls enable the first entity to interrupt existing calls over the controlled telephone line.

Abstract: By selecting access points specific to the various components of call-content of a call, a monitoring agency is ensured of obtaining the call-content of each participant in telephone call irrespective of call transfers and network reconfiguration. Devices in the telecommunications system such as network devices can provide appropriate access. Examples of suitable network devices may include gateway, an access gateways, trunk gateways, portals, ATM switches, routers, and border elements.

Abstract: A method, system, and program for telephony based remote location monitoring are provided. A telephone network receives the caller request to listen only to a remote location telephony device. The telephone network allocates a listen only channel between the caller telephony device and the remote location telephony device. The telephone network activates a microphone at the remote location telephony device via the listen only channel. Then, audio detected at the microphone is streamed via the listen only channel to the caller telephony device, such that the telephone network enables a caller to monitor a remote location through the remote location telephony device with minimized allocation of telephone network resources.

Abstract: The present invention discloses a method and apparatus for determining and reporting the operational status of an integrated services hub. The AC power supply and wide area network connection of the integrated services hub are monitored, and a signal is sent to a user upon detecting a problem. The AC power supply is preferably monitored through a bit on a power supply status register. The wide area network connection is preferably monitored through a network status register on a line interface chip or chip set residing in the integrated service hub and connected to the wide area network. The warning signal is preferably an audible warning tone played through a telephone receiver connected to the integrated services hub.

Abstract: A reception result of an analog signal transmitted from a local switch to a subscriber line, or a voltage difference corresponding to a line current is analyzed, and a transmission characteristic in the subscriber line is evaluated based on an analyzing result. The transmission characteristic is sent to a network by use of a function of an analog transmitting unit. Noises having power of a predetermined threshold value or more are detected from a data signal input to a digital transmitting unit, and a periodicity of the noises is examined, whereby influences of the cyclic noises are evaluated, and an examination result is sent to the network by use of the function of the analog transmitting unit. As a result, provided is an xDSL modem capable of automatically collecting various characteristics of the subscriber line connected thereto prior to a start of a provision of a broadband communication service.

Abstract: A remote test unit (RTU) and method of operation are provided for utilizes the ability of an access matrix ability to route signals. The RTU can emulate a central Digital Subscriber Line Modem (DSLM-C) for testing customer premises equipment containing a remote Digital Subscriber Line Modem (DSLM-R). The RTU can also emulate a DSLM-R for testing central offices equipment including a digital subscriber line access multiplexer (DSLAM) containing a DSLM-C. The RTU can also emulate a concentrator connected to the DSLAM, a router connected to the concentrator, an Internet service provider (ISP) connected to the router, and a web site connected to the ISP over the Internet. The RTU can further test, using emulation, ISO/OSI layers defined in the ISO/OSI reference model which are connected to the DSLAM.

Abstract: A wireless telephone backup device for landline telephone equipment that may be located on the customer side of the landline service connection, typically in a restricted access location, such as an attic, basement, or utility closet. An interconnection circuit in the backup device detects service interruptions in the subscriber's landline connection and, in response, powers on a wireless communication device to provide backup telephone service to the customer premises equipment. The interconnection circuit also provides the other features standard landline telephone service, including dial tone, ring voltage, and normal dialing for outgoing calls. The backup device also forwards incoming landline calls to the wireless unit in the backup device, and may send a message notifying a maintenance center of the service interruption. Further, the backup device may initiate an indicator in an alarm system at the site of the customer premises equipment to notify the subscriber of the service interruption.

Abstract: Methods and systems for providing lawful intercept of a media stream in a media gateway include establishing a call context between a first termination and a second termination and establishing a tap context with at least one tap termination, which refer to the first termination. The call context defines a call media stream between the first and second terminations associated with a call between first and second end users. The tap context defines at least one tap media stream from the first termination to the at least one tap termination. The tap media stream is a one-way media stream that carries either the mouth portion of the call media stream, the ear portion of the media stream, or a combination of the mouth and ear portions of the media stream from the first termination to the at least one tap termination. Multiple tap contexts can be created to support the lawful intercept of the call by multiple law enforcement agencies.

Abstract: A dispatch based call system configured to contact a call center using a single unique name or number. Multiple users are able to simultaneously dispatch the single generic call center number and communicate with a unique end station or individual at the call center. A user, or subscriber unit, when dispatching a call communicates initially with the service provider infrastructure. The infrastructure then establishes communication with the call center. The call center determines the identifier of an available end station and the subscriber is subsequently connected to the available end station.

Abstract: An impedance blocking filter circuit is provided for use in telecommunication systems for interconnecting between incoming telephone lines and customer's terminal equipment so as to unconditionally block impedances above 20 KHz due to the customer's terminal equipment from an ADSL network unit and/or home networking interface unit. The filter circuit includes first, second, and third inductors connected in series between a first input terminal and a first common point. A first resistor has its one end connected also to the first common point and its other end connected to a first output terminal. Fourth, fifth and sixth inductors are connected in series between a second input terminal and a second common point. A second resistor has its one end also connected to the second common point and its other end connected to a second output terminal. A capacitor has its ends connected across the first and second common points.

Abstract: An impedance blocking filter circuit is provided for use in telecommunication systems for interconnecting between incoming telephone lines and customer's terminal equipment so as to unconditionally block impedances above 20 KHz a desired frequency range due to the customer's terminal equipment from an ADSL a DSL network unit and/or home networking interface unit. The filter circuit includes first, second, and third inductors connected in series between a first input terminal and a first common point. A first resistor has its one end connected also to the first common point and its other end connected to a first output terminal. Fourth, fifth and sixth inductors are connected in series between a second input terminal and a second common point. A second resistor has its one end also connected to the second common point and its other end connected to a second output terminal. A capacitor has its ends connected across the first and second common points.