Abstract: A testing circuit for use in an inductive coupling system to test communication devices is disclosed. The testing circuit including at least an output transformer having a frequency response for providing a signal having electrical properties compatible with a communication device to be tested; and, a spectral shaping circuit having an input port for receiving a test signal and an output port for providing a shaped test signal, the shaped test signal for being provided via the at least an output transformer to a device under test, the spectral shaping circuit for partitioning the test signal in dependence upon pre-determined spectral ranges thereof and relating to a frequency response of at least an output transformer for shaping the frequency characteristics of the received signal in approximately inverse proportion to the frequency response of the at least an output transformer.

Abstract: A method and apparatus for calculating and inserting a TCP checksum neutralizing value into a network data packet in a manner which minimizes storage requirements and processing time used to process the data packet. In one embodiment, a checksum is calculated as a data packet is being received, up to the checksum field. The calculated checksum is then inserted into the checksum field. Then the remaining fields used to calculate the TCP checksum are summed. The inverse of this sum is then stored in a normally unused portion of the payload portion of the data packet near the end of the packet. When the packet is received and the TCP checksum is calculated, since the inverse of the fields which were not used to calculated the checksum in the TCP header is in the payload portion, their contribution to the checksum is negated so that a comparison of the calculated checksum and the stored TCP checksum will match, assuming the packet was properly received.

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.

Abstract: An electrical cable includes one or more conductors with one or more shields encircling the one or more conductors. Each of the shields includes a conductive layer with a nonconductive layer electrically separating the conductive layer from one another. Connection mechanisms to the conductive layers can be through the use of a plurality of drainwires, which are each in substantially continuous contact with one conductive layer of at least one shiel. Each of the connection mechanisms is eletrically separated from other conductive layer of other shields and from the other connection mechanisms. Each connection mechanism and conductive layer in contact therewith can constitute an electrode that is electrically connectable at an end of the cable.

Abstract: An embodiment of the invention provides a mechanism for measuring the performance characteristics of data sent across any communication path configured to carry data between two or more computational devices (e.g., local area networks, wide area network, virtual private networks, wireless networks, or any other type of interconnect mechanism). In a test environment, processing speed is a critical part of producing test equipment that can process network protocol data in real-time. Embodiments of the invention provide network test equipment with a methodology for performing enough lookup processing operations to keep up with the real time frame rates of a gigabit Ethernet network. This is accomplished in accordance with one embodiment of the invention by improving the performance of the connection lookup processor in test devices.

Abstract: A system for diverting an optical component signal from a multiplexed optical signal includes an optical communications channel having a first portion and a second portion. A multiplexed optical signal having a plurality of component signals may be transmitted through the optical communications channel. Each component signal lies within a different optical bandwidth. The system also includes a branch optical channel having a first section and a second section. A signal diverter that optically couples the first portion of the communications channel to the second portion of the communications channel directs a diverted portion of the multiplexed optical signal into the first section of the branch optical channel. The signal diverter also allows a non-diverted portion of the multiplexed optical signal to propagate into the second portion of the optical communications channel.

Abstract: A method and apparatus for inserting sequence number and timestamp information into a network data packet in a manner which is checksum neutral with respect to a checksum precalculated in the network protocol portion of the data packet. The checksum neutral addition of sequence number and timestamp is accomplished by in addition to adding to the payload portion a sequence number and timestamp, also adding a value which is a modified version of the sequence number and of the time stamp such as an inverse value.