In telecommunications, a toll switching trunk or toll connecting trunk is a trunk connecting an end office to a toll center as the first stage of concentration for intertoll or long-distance traffic.
Operator assistance or participation may be an optional function. In U.S. common carrier telephony service, a toll center designated Class 4C is an office where assistance in completing incoming calls is provided in addition to other traffic; a toll center designated Class 4P is an office where operators handle only outbound calls, or where switching is performed without operator assistance.
References
- The Digital Future, 1979 Toll connecting trunk
- "4A Toll Switching System" (PDF). Archived (PDF) from the original on 2022-10-09.
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188).
See also
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