Ключевые слова:
Communication networks, Computer networks, Telephone networks, Telephony, Telecommunication systems, Telecommunication, Information exchange, Data transfer, Data transmission, Private networks, Private integrated services network, Open systems interconnection, Network layer (OSI), Radiocommunication, Access, Message switching networks, Data processing, Data transmission control procedures, Data layout, Signal transmission, Addresses (data processing), ISDN, Data security, Data storage protection, Protocols, PINXs