Hackish way of referring to the plain old telephone system, comparing it to a digital network. Usenet sig blocks sometimes include the sender's telephone number next to a "Voice:" or "Voice-Net:" header; variants of this are "Voicenet" and "V-Net".
Compare paper-net, snail-mail.
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Nearby terms: vocoding « VoD « voice mail « voice-net » Voice over IP » voice recognition » VoIP