# \#telephone-switching

**URL:** https://scanalyst.fourmilab.ch/tag/telephone-switching/3051.md

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## [Cutting Over an Electromechanical Telephone Exchange to Electronic Switching](https://scanalyst.fourmilab.ch/t/cutting-over-an-electromechanical-telephone-exchange-to-electronic-switching/2996)

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**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [4 April 2023 12:55 UTC](https://scanalyst.fourmilab.ch/t/cutting-over-an-electromechanical-telephone-exchange-to-electronic-switching/2996 "2023-04-04T12:55:05Z")

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In computer system administration, we often speak of the “cutover” from one system (hardware, software package, etc.) to a new one, in which the goal is to minimise the service outage and disruption to user…

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## [Green Goo vs. a Telephone Central Office Crossbar Switch](https://scanalyst.fourmilab.ch/t/green-goo-vs-a-telephone-central-office-crossbar-switch/2609)

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**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 2\
**Last updated:** [15 January 2023 16:33 UTC](https://scanalyst.fourmilab.ch/t/green-goo-vs-a-telephone-central-office-crossbar-switch/2609 "2023-01-15T16:33:50Z")

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For decades (1940s through the early 1990s), the Number Five Crossbar Switch was a mainstay of the Bell Telephone System in the United States. Originally designed for smaller central offices with between 3…

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## [Debugging an Electromechanical Telephone Crossbar Switch with a Trouble Recorder](https://scanalyst.fourmilab.ch/t/debugging-an-electromechanical-telephone-crossbar-switch-with-a-trouble-recorder/2419)

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**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 1\
**Last updated:** [10 December 2022 20:26 UTC](https://scanalyst.fourmilab.ch/t/debugging-an-electromechanical-telephone-crossbar-switch-with-a-trouble-recorder/2419 "2022-12-10T20:26:54Z")

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The No. 5 crossbar telephone switching developed by the Bell System in the United States was fantastically complicated and composed of myriad electromechanical components which had to work reliably for long…

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## [Telephone Switching Living History in Seattle](https://scanalyst.fourmilab.ch/t/telephone-switching-living-history-in-seattle/2175)

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**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [21 October 2022 16:37 UTC](https://scanalyst.fourmilab.ch/t/telephone-switching-living-history-in-seattle/2175 "2022-10-21T16:37:25Z")

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