A method and system for managing performance of over a multimedia content distribution network (MCDN), such as a digital subscriber line network, involves receiving an indication of an impairment in network performance from an MCDN client. The MCDN node associated with the client may be identified and a community of MCDN clients coupled to the MCDN node may be further identified. Impairment information, representative of MCDN equipment, may be collected for each of the MCDN clients. Detailed network diagnostics and field service may be performed for MCDN clients based on a characterization of the impairment parameters. After remediation of the MCDN node, collection of the impairment information may be terminated.

Regenerator devices (30) for use with Digital Subscriber Line (DSL) connections are disclosed which forward user data received in a modulated signal from one link (L1) of a DSL connection on to another link (L2) of the DSL connection. Such devices comprise a first transceiver module (302) which receives a modulated signal from the first link and demodulates it whereby to obtain user data, and a second transceiver module (306) which receives the user data obtained by the first transceiver module and transmits a modulated signal carrying it on to the other link. The device further comprises a performance analyzer (308) which obtains performance information in respect of the second link, and a profile management processor (307) which determines a profile to be applied in respect of the second link in dependence on the performance information obtained in respect thereof. An access net work including one or more such devices and associated methods are also disclosed.

A method and system for managing performance of over a multimedia content distribution network (MCDN), such as a digital subscriber line network, involves receiving an indication of an impairment in network performance from an MCDN client. The MCDN node associated with the client may be identified and a community of MCDN clients coupled to the MCDN node may be further identified Impairment information, representative of MCDN equipment, may be collected for each of the MCDN clients. Detailed network diagnostics and field service may be performed for MCDN clients based on a characterization of the impairment parameters. After remediation of the MCDN node, collection of the impairment information may be terminated.

Detecting PIM in a downstream signal, wherein the downstream signal is received from a cable plant via a subscriber network and an upstream signal is transmitted to the cable plant via the subscriber network. The upstream signal is transmitted in bursts during active intervals. PIM arises from an interaction between the upstream signal and a nonlinear component in the subscriber network and occurs in bursts corresponding to the upstream signal. The detection steps are: (a) identifying the potentially affected downstream signal from the upstream signal; (b) receiving the downstream signal during an active interval; (c) measuring a metric of the downstream signal to obtain an active value; (d) receiving the downstream signal during a quiet interval; (e) measuring the metric of the downstream signal to obtain a quiet value; (f) comparing active and quiet values; and (g) determining whether PIM distortion has been detected based on the comparison.

A video stream DSL analyzer receives at least non-physical layer management data and physical layer management data and in response generates metric information. The generated metric information is used to characterize the performance of the video stream information and diagnose any problems if necessary. In response to the metric information, the video stream DSL analyzer changes one or more DSL configuration(s) in order to improve performance.

A method for retiming digital telecommunications data received by a digital logger from a plurality of T-carrier type telephone lines respectively having differing clock sources ensures efficient transmission of received digital audio data to a host computer via a Universal Serial Bus (USB) interface. Also the digital logger includes volatile memory for temporarily storing digital audio data received from the plurality of T-carrier type telephone lines for: 1. ensuring that the host computer receives digital audio data correctly via the USB interface; 2. buffering the digital audio data within the digital logger during interruptions in transmission of digital audio data from the digital logger via the USB interface; and 3. reducing audible latency of speech communications.

Detecting PIM in a downstream signal, wherein the downstream signal is received from a cable plant via a subscriber network and an upstream signal is transmitted to the cable plant via the subscriber network. The upstream signal is transmitted in bursts during active intervals. PIM arises from an interaction between the upstream signal and a nonlinear component in the subscriber network and occurs in bursts corresponding to the upstream signal. The detection steps are: (a) identifying the potentially affected downstream signal from the upstream signal; (b) receiving the downstream signal during an active interval; (c) measuring a metric of the downstream signal to obtain an active value; (d) receiving the downstream signal during a quiet interval; (e) measuring the metric of the downstream signal to obtain a quiet value; (f) comparing active and quiet values; and (g) determining whether PIM distortion has been detected based on the comparison.

Automatic testing/analysis of local loops of telecommunications networks includes obtaining bits-per-tone data for a local loop of a telecommunications network and generating a bit value string from the bits-per-tone data. The bit value string is then analyzed to determine whether it includes a bit pattern indicative of an impairment of the local loop. Further approaches for automatically testing local loops of telecommunications networks include obtaining attenuation data for multiple tones carried by the local loop and determining whether the attenuation data falls below thresholds for providing a service using the local loop.

Upon detection of a trigger, such as the exceeding of an error threshold or the direction of a user, a diagnostic link system enters a diagnostic information transmission mode. This diagnostic information transmission mode allows for two modems to exchange diagnostic and/or test information that may not otherwise be exchangeable during normal communication. The diagnostic information transmission mode is initiated by transmitting an initiate diagnostic link mode message to a receiving modem accompanied by a cyclic redundancy check (CRC). The receiving modem determines, based on the CRC, if a robust communications channel is present. If a robust communications channel is present, the two modems can initiate exchange of the diagnostic and/or test information. Otherwise, the transmission power of the transmitting modem is increased and the initiate diagnostic link mode message re-transmitted to the receiving modem until the CRC is determined to be correct.

Disclosed is a technique for estimating crosstalk between a first and second electrical transmission lines. The method comprises obtaining measurements of a received near end crosstalk, NEXT, signal, the NEXT signal being received at a first end of the second transmission line over a time period as a result of an electrical signal sent onto the first transmission line from its first end, the obtained measurements being in the time domain. Subsequently, a crosstalk coupling estimate is obtained per transmission line sub-interval by compensating the obtained measurements in the time domain of the received NEXT signal for round-trip attenuation of the sent signal from the first end of the first line to the sub-interval and back to the first end of the second line, and an estimate of a total crosstalk coupling is obtained by adding together at least some of the obtained crosstalk coupling estimates per transmission line sub-interval.