| Descriptors | Telephone networks, Public switched telephone network, Electronic telephone switching systems, Analogue circuits, Telephone equipment, Telephony, Analogue signals, Interfaces (data processing), Interfaces, Electric connectors, Electric terminals, Communication equipment, Telecommunication systems, Performance, Signal transmission, Electric sockets, Classification systems, Direct current, Radiocommunication, Noise (spurious signals), Signal level, Signal strength, Electrical impedance, Approval testing, Performance testing, Test equipment, Testing conditions, Accuracy, Electrical testing, Circuits Network interconnection |
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