Timeline Filter by: Decade or Famous Calls The Network The Business
Early tech | Electronics | Wireless | Digital | Operators | Cables and wires | Exchanges | Phreaking/Hacking | Dialing | Switching | Telegraph | Wired Tech | Office systems | Payphones | Data services | Line workers | Operations
Doolittle files patent for 'direct-connecting' switchboard
Thomas B. Doolittle
1877
Puskas introduces the multiplex switchboard
Tivadar Puskás
1887
Almon Strowger invents the automatic switch
Almon Strowger
1889
Strowger forms Automatic Electric Company, receives switch patent
Almon Strowger
1891
First Strowger automatic exchange opens (in LaPorte, Indiana)
First Strowger automatic exchange opens (in LaPorte, Indiana)
1892
Crossbar switching introduced
Crossbar switching introduced
1938
The Step-By-Step Switch
The Step-By-Step Switch
1951
A Surreal Look at Telephone Switching
A Surreal Look at Telephone Switching
1958
Electronic Switching System Debut (Bell System)
Electronic Switching System Debut (Bell System)
1965
World's first electronic telephone switch (No. 1 ESS) installed
World's first electronic telephone switch (No. 1 ESS) installed
1965
Under London Trunk Telephone
Under London Trunk Telephone
1968
First 'plugless' digital operator stations (TSPS), in Morristown, NJ
First 'plugless' digital operator stations (TSPS), in Morristown, NJ
1969
Hoover invents computerized call switching
Erna Schneider Hoover
1971
First digital switch (No. 4 ESS) deployed
First digital switch (No. 4 ESS) deployed
1976
Northern Telecom DMS-100 digital switch
1978
Siemens debuts digital telephone switching
1980
Speedy Cutover Service, SXS to ESS (AT&T)
Speedy Cutover Service, SXS to ESS (AT&T)
1984
SS7 signaling becomes widespread
1991