A blue box is an unauthorized electronic device that generates the same tones employed by a telephone operator's dialing console to switch long-distance calls. A blue box is a tool that emerged in the 1960s and 70s; it allowed users to route their own calls by emulating the in-band signaling mechanism that then controlled switching in long distance dialing systems. The most typical use of a blue box was to place free telephone calls. A related device, the black box enabled one to receive calls which were free to the caller. The blue box no longer works in most Western nations, as modern switching systems are now digital and do not use in-band signaling. Instead, signaling occurs on an out-of-band channel which cannot be accessed from the line the caller is using, a system called Common Channel Interoffice Signaling or CCIS.
Read more about Blue Box: History, Operation, Frequencies and Timings, Special Codes, Blue Boxes in Other Countries
Famous quotes containing the words blue and/or box:
“The Reverend Samuel Peters ... exaggerated the Blue Laws, but they did include “Capital Lawes” providing a death penalty for any child over sixteen who was found guilty of cursing or striking his natural parents; a death penalty for an incorrigible son; a law forbidding smoking except in a room in a private house; another law declaring smoking illegal except on a journey five miles away from home,...”
—Administration for the State of Con, U.S. public relief program (1935-1943)
“To be black and an intellectual in America is to live in a box.... On the box is a label, not of my own choosing.”
—Stephen Carter (b. 1954)