Testers for telecommunication lines; computer software for testing and maintaining telecommunication and computer systems; electronic test instruments for the communications and computer industry, namely for testing the characteristics of communication media as well as the signal transported by such media including signal bandwidth, signal power, signal strength, signal attenuation, signal loss, insertion loss, return loss, environmental noise, cross talk, data rate, voltage, impedance, frequency, amplitude, wattage, power spectral density, applied longitudinal voltage, longitudinal balance, measured voltage, modulation and multiplexing, line length, line suitability, thermo/mechanical effects on signal, throughput, insulation, taps, splits, signal boost strength, breaks, shorts and resistance of signal transport media and for use in testing communications and computer systems, data transmitting devices and data receiving devices; electronic devices for testing input data waveform systems and synchronous data distortion in telephone installations and parts for all the aforesaid goods

Maintenance of telephone installations, communication equipment, telecommunication and computer system testing equipment, telecommunications and computer systems, featuring the use of electronic circuits and associated software