A trunk call, also known as a long-distance call or a toll call, refers to a telephone call made between two parties located in different geographical areas that are connected by a long-distance telephone network. In the past, when most telephone calls were manually connected by operators, a trunk line was used to establish the connection between distant cities or regions.
Here's how a trunk call worked in the earlier days of telecommunications:
Local Exchange: Each local area or city had its own telephone exchange. If you wanted to make a call within the same city, you would connect to the local exchange, and the call would be handled by the operators there.
Trunk Lines: For calls between different cities or regions, trunk lines were used. These were long-distance telephone lines connecting one telephone exchange to another. When a caller in one city wanted to reach someone in another city, they would request a trunk call.
Operator Assistance: Making a trunk call required operator assistance. The caller would connect to a local operator, provide the number they wanted to call, along with the city or region they wanted to reach. The local operator would then establish a connection with the distant exchange's operator.
Long-Distance Charges: Trunk calls were often more expensive than local calls because they involved the use of long-distance infrastructure and operator assistance. Callers were typically billed based on the duration of the call and the distance between the two locations.
With the advancement of technology, the manual operator-based system has largely been replaced by automated systems, and long-distance calls are now commonly made using digital networks like fiber optics and satellite communication. Today, making a long-distance call is often no different from making a local call, as most phone plans include long-distance minutes or offer flat-rate calling across different regions.