Autovon

[2] In 1969, AUTOVON switching centers opened in the United Kingdom, and later in other European countries, Asia, the Middle East, and Panama.

It was a major part of the Defense Communications System (DCS), providing non-secure switched voice services.

In the US the cables were predominantly L-carrier coaxial multiplex built by AT&T, who also used them to carry about one third of all civilian long-distance calls, as their capacity was much higher than the military needed.

Most of the cable repeater huts have been sold to private interests, to round out existing parcels, or as possible build-to-suit tower sites, etc.

[needs update] The AUTOVON system provided a facility for placing calls with multilevel precedence and preemption (MLPP).

This system inspired similarly survivable ones for message networks, including in future decades the Internet.

Local base switches would be connected to a few AUTOVON trunks, which the user would access by dialing 8 (or in some cases, 88) before the telephone number.

The United States Department of Defense (DoD) charged access to AUTOVON according to a complex billing system, and each base budgeted according to local practice.

Equipment is housed in a network of redundant and distributed deep underground facilities spread across the globe, each of which are capable of withstanding multiple direct nuclear attacks of very significant yield.

All equipment is housed in such a way that it can absorb multiple blast waves propagating underground while still maintaining continuous operation.