Silver box

{
  "id": "MLC-T-IND-005286",
  "term": "Silver box",
  "field": "Industrial and trades",
  "definition": "A type of tone generator used to produce the 2600 Hz single-frequency tone required to manipulate early long-distance telephone switching systems. As a form of phreaking tool, it allowed a user to seize a trunk line and place unauthorized calls by mimicking the signals used by telephone operators. The device is a historical artifact from the era of in-band signaling, which was superseded by more secure common-channel signaling systems like SS7.",
  "subject": "Electrical engineering",
  "translations": {
    "de": "Silver Box",
    "es": "caja plateada",
    "fr": "boîtier argenté"
  },
  "url": "https://mlchart.com/terminology/industrial/silver-box/"
}