9 electronic air traffic control and air defense voice communication switching units, communication consoles, and electronic flight information display units which provide voice communication between control positions and radios or telephones and which provide conference connections among them; simultaneous voice and data transmission units, (namely, digital voice switching systems and high-speed data buses to transport voice and data traffic); fiber optic transmission equipment, (namely, multiplexers for routing voice data and video over fiber optic transmission lines); video conferencing products which combine voice, video, and data in a personal computer-based format as well as stand-alone; information security software to limit access to UNIX-based computers at the operating system level and information security hardware (such as secure facsimile equipment); parts and apparatus for the above goods