Pillar Guide & Keyword Hub
PSTN & Legacy History
Early mechanical switching, phone phreaking, 2600Hz whistle, blue box era.
Historical Events in PSTN & Legacy History
1837Signaling Plane
The Optical Telegraph Hack (Chappe Semaphore)
Francois and Joseph Blanc hijacked the French optical telegraph network by bribing operators to insert deliberate backspace/error codes into stock market transmissions.
1844Data Plane
First Public Telegraph Line & Wiretap Vulnerability
Samuel Morse transmitted the first message ("What hath God wrought"), exposing physical wiretapping along unencrypted DC lines.
1957Signaling Plane
Joe Engressia ("Joybubbles") Discovers 2600 Hz Whistle Exploit
Seven-year-old blind boy Joe Engressia discovered that whistling 2600 Hz into a receiver reset AT&T toll trunk lines.
1964Voice Plane
AT&T MF Switching & The Captain Crunch Blue Box Era
John Draper ("Captain Crunch"), Steve Jobs, and Steve Wozniak built Blue Boxes using 2600 Hz toy whistles to make free global calls.
1990Signaling Plane
AT&T Long Distance Network Collapse
A software bug in AT&T 4ESS switches caused a cascade of SS7 recovery messages, dropping 60,000,000 calls over 9 hours.