switching and transmission equipment, namely, voice and data switching systems comprising two or more of the following - circuits switching, message switching, control, peripheral interface, mass storage, bulk data transfer, digital service units, and networks, attendant consoles, multiplexer-demultiplexers; telephones; and parts of the aforesaid goods; telecommunications products, namely, communication controllers, security telephone line surveillance monitors, coin free paystation converters, telephone line drivers, telephone line automatic ground start circuits, telephone toll controllers, telephone line security access controllers, centrex call concentrator controllers, redialers, datasets, tone to pulse converters, call detailing reporting units; and parts of the aforesaid goods; semiconductor devices namely, integrated circuits, filters, switching circuits, logic circuits, bus transceivers, data line drivers, pulse dialers, liquid crystal display drivers, switch arrays, analog and digital line interface circuits, dual tone multifrequency decoders, filters, receivers and transceivers, bus access circuits, subscriber network access circuits, phase lock loops, subscriber loop extender circuits, trunk interface circuits, telephone circuits, equaliser circuits, speech processing circuits, signal protocol converters, signal protocol generating circuits, and hybrid circuits incorporating the above; computer programs for use in the telecommunications and related fields, and installation and maintenance manuals distributed with the aforesaid goods; adjunct processors for computer-augmented telephony, telephone line terminal adaptors, voice call branders, alternative operator access controllers, universal signalling adaptors, local area network interface circuits, encryption and decryption circuits, computers; and parts of the aforesaid goods