Abstract: Timestamp information can be placed in a frame that includes a first portion processable at a selected layer of a protocol stack and a second portion processable at a lower protocol layer of the protocol stack subsequently to the processing of the first portion, wherein the first portion is contained within the second portion and wherein a numerically computed error detection code for the second portion is computed during processing of the second portion. A timestamp signature having a timestamp subfield of initialized data and a corrector subfield of initialized data is embedded in the first portion during processing thereof at the selected protocol layer. A numerical constant functionally equivalent to the numerically computed error detection code is determinable from the initialized data in the timestamp subfield and the corrector subfield. The data in said timestamp subfield is modified with timestamp information subsequently to processing of the second portion at the lower protocol layer.

Abstract: A system for diagnosing impairments in computer networking services a plurality of connector gateways for interfacing to a plurality of data sources to provide access by the system to computer network data, business-related data, and extra-enterprise environmental data in the plurality of data sources. The system includes a knowledge manager in communication with each of the plurality of connector gateways for analyzing data from the plurality of data sources to generate diagnostic conclusions for resolving the impairments in the computer networking services. The system also includes an interactor in communication with the knowledge manager for generating format information for displaying at least the diagnostic conclusions to a user. The system can include a graphical user interface for displaying at least the diagnostic conclusions associated with edges of an edge model of the computer networking services of the user.

Abstract: The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a first current source and a second current source are disposed in series with a node therebetween coupled resistively to a wire of the wire pair. A current flow path is provided for balancing the current from the two current sources. A similar circuit is also coupled to the other wire of the wire pair.

Abstract: Apparatuses and methods for testing the integrity of high speed optical fiber transmission networks are presented. Data from an optical network, for example, NRZ formatted data at forty gigabits per second and higher may be reliably recovered using embodiments of the invention. The invention employs hybrid microwave and high speed processing technology to reliably measure the phase shift of the data transmitted over a high speed optical transmission network by comparing the incoming data to a super-stable clock/frequency reference. The clock/frequency reference is intentionally offset by fractional frequency resulting in a beat frequency when compared to the incoming data. The beat frequency provides the ability for automatic calibration of the phase measurements because the period of the full 360 degrees phase is known. Also, the invention provides reliable means for measuring jitter and for generating Eye-pattern diagrams by eliminating issues associated with oscilloscope loop bandwidth limitations.

Abstract: An invention is provided for testing a quality of communication data received from a SUT. The invention includes storing reference test data comprising a plurality of data segments, and receiving degraded test data also comprising a plurality of data segments, from the SUT. The data segments are located in the degraded test data, and data segments in the degraded test data are matched to related data segments in the reference test data. Further, the data segments in the degraded test data are compared to corresponding data segments in the reference test data using a fixed point operation. In one aspect, the degraded test data can be normalized prior to locating the data segments, for example, utilizing a fixed point Fourier transform. Also, a receive filter can be applied to the normalized test data utilizing a fixed point operation.

Abstract: A system for mitigating noise associated with information communication includes means for determining when a first set of information is transmitted by a transmitter. The system includes a receiver for receiving a second set of information in response to the first set of information. The system also includes control means for temporarily suspending at least one process when the determining means determines that the first set of information is being transmitted and for continuing the at least one process after the second set of information has been received by the receiver. The at least one process produces noise that interferes with an integrity of the second set of information received by the receiver.

Abstract: A monitor access is gradually applied an removed from a communications circuit, including a digital subscriber line (DSL), by a gradual monitor access (GMA) technique, in which a variable impedance element is gradually applied to the communications circuit until the monitor can be introduced to the communications circuit without data disruption.

Abstract: The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a differential mode noise signal is received at a first and a second input port, which are connected via a first and a second resistor to a first and a second end tap of a primary coil of a transformer, respectively. The transformed differential mode noise signal is then transmitted via a first and a second end tap of a secondary coil of the transformer and a third and a fourth resistor to a first and a second output port for injection at high impedance into a first and a second wire of the communication link. Optionally, the device comprises a third input port connected to a center tap of the secondary coil for receiving a common mode noise signal. The common mode noise signal is then provided at low impedance to the first and the second wire via the first and the second end tap of the secondary coil and via the third and fourth resistor having low impedance, respectively.

Abstract: In a system and method for producing functions for generating pseudo-random bit sequences, an extended shift register (ESR) is formed. Each bit in the ESR is shifted to a next higher bit and the lowest-order bit is replaced with an EXCLUSIVE-OR operation of at least two other bits in the ESR. A plurality of bit equations is generated. For each bit equation, a bit in the ESR is replaced with an AND operation between shifted contents of the ESR and one of a plurality of first bit masks that isolate the bit. Each of the plurality of bit equations is combined. Shifts of the same shift distance are merged. Redundant bit masks are removed. Bit masks are transformed into bit masks comprising a sequence of zero bits and one bits. Bit masks are replaced with bit shift operations to form a function for generating the pseudo-random bit sequences.

Abstract: A computer implemented method for generating a test plan for a communication device under test. The test plan defines test tools, test methodologies, test configurations, and algorithms for executing the test. A user input is received to define the communication device under test. Next, a knowledge database is searched to identify test plan parameters for the communication device under test. Thereafter, the test plan parameters and the user input are analyzed to identify the test plan. A system and computer readable medium having program instructions for generating a test plan for a communication device under test are also described.

Abstract: Methods for configuring a test setup that support reuse of previously defined sub-configuration parameter values without reference to individually-named sub-configuration files are provided. In these methods, each sub-configuration parameter value is automatically associated with a test case name within the test, and this association is represented in context data structures. During test configuration, for each set of sub-configuration parameter values, the user may reuse previously-defined values simply by specifying the name of the test associated with the previously-defined values. A system and a user interface for configuring a test setup are also described.

Abstract: The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a first current source and a second current source are disposed in series with a node therebetween coupled resistively to a wire of the wire pair. A current flow path is provided for balancing the current from the two current sources. A similar circuit is also coupled to the other wire of the wire pair.

Abstract: An embodiment of the invention comprises a method and system for testing a networking system's performance. The invention solves a problem related to upgrading system components associated with different steps of the testing process for networking systems. Systems embodying the invention comprise a processing apparatus and a testing apparatus, each of which contains a data bus. The two data buses are linked together through a bi-directional communication bridge that allows the testing apparatus and the processing apparatus to transparently communicate such that the bridged data buses behave as through they exist on a same local bus. The architecture provided by the invention allows for the upgrading of a processing apparatus for enhanced data processing performance without changing existing adequate testing devices.

Abstract: A fault-testing node for a connectionless data link has at least two opposing communication ports; a soft switch for controlling port-to-port data flow through the device; and an instance of software for modifying packet header information. The node enables loop-back testing by one or more port-to-port data flow paths being switched through activation of the soft switch to loop incoming packets back to the sender of the packets through the device and wherein the instance of software reverses the order of source and destination addresses of data units to insure acceptance of looped data units at the sender station.

Abstract: A system for monitoring a plurality of communication circuits includes an impedance element configured to be switchably connected to one of the plurality of communication circuits. The impedance element is configured as a short circuit relative to the one of the plurality of communication circuits. The system includes an AC current mirror in communication with the impedance element. The system includes a monitor access element in communication with the AC current mirror. The system includes a communication circuit monitor configured to be connected to the monitor access element. To monitor the one of the plurality of communication circuits, the impedance element is switchably connected to the one of the plurality of communication circuits, thereby connecting the communication circuit monitor to the one of the plurality of communication circuits with a minimum of disruption to data communication within the one of the plurality of communication circuits.

Abstract: A monitor access is gradually applied an removed from a communications circuit, including a digital subscriber line (DSL), by a gradual monitor access (GMA) technique, in which a variable impedance element is gradually applied to the communications circuit until the monitor can be introduced to the communications circuit without data disruption.

Abstract: A monitor access is gradually applied an removed from a communications circuit, including a digital subscriber line (DSL), by a gradual monitor access (GMA) technique, in which a variable impedance element is gradually applied to the communications circuit until the monitor can be introduced to the communications circuit without data disruption.

Abstract: A system for determining characteristics associated with a communication channel includes a transmitter for transmitting a first signal via the communication channel. The system includes a receiver for receiving a second signal via the communication channel in response to the first signal. The second signal is associated with the first signal. The system includes a correlator for performing frequency domain correlation between a frequency domain representation of the second signal and frequency domain representations of a plurality of time-delayed versions of the first signal to generate frequency domain correlation information. The system includes an analyzer for identifying correlation peaks in a magnitude of the frequency domain correlation information to determine locations of discontinuities of the communication channel. The identified correlation peaks are associated with the locations of the discontinuities of the communication channel.

Abstract: A system for monitoring a communications circuit includes at least one impedance element connected to the communications circuit when the communications circuit is established. Communication devices communicating via the communications circuit adapt to the presence of the at least one impedance element. Each impedance element is switchably connected to a respective reference ground point. The system includes at least one monitor access element configured as a virtual reference ground point. Each impedance element is switchably disconnected from a respective monitor access element. The system includes at least one communications circuit monitor connected to the respective monitor access element. To monitor the communications circuit, the at least one impedance element is switchably connected to the respective monitor access element and switchably disconnected from the respective reference ground point.

Abstract: An invention is provided for testing telecommunications devices. Broadly speaking, test data is encoded prior to testing a SUT. Then, during testing, the encoded test data is transmitted to the SUT, which processes the test data. The processed test data then is received back from the SUT. The processed test data is decoded in real-time, as opposed to the encoding of the test data, which is performed offline and prior to testing. In addition, a quality of the processed test data is analyzed. Typically, the test data is speech data, which is stored prior to testing the SUT. Optionally, the speech data can be encoded offline using a computer system separate from the testing system.