Nonblocking minimal spanning switch

A nonblocking minimal spanning switch is a concept developed in the 1950s to reduce the costs of telephone exchanges in the Bell System by reducing the number of the most expensive components of a telephone switch. This reflects a key problem in the AT&T Bell System prior to divestiture in 1984, which was providing satisfactory (from the customer point of view) end-to-end service at the lowest possible cost.

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