Trunk vs Toll
Encyclopedia
In the US, under the purview of the Bell System
, local telephone
calls were flat rate
; i.e., included in the subscribers' fixed fees except in a few big cities, and the term toll was adopted
for long distance call
s because they were subject to tolls.
In the UK
all calls were chargeable and the term trunk
was adopted for long distance calls. Initially a trunk call had to be booked in advance and an operator
would call the subscriber when the call could be put through. In 1921 the first toll exchange was opened which allowed the shorter-distance trunk calls to be connected while the subscriber waited. The name toll was probably taken from US usage.
In the London telephone area, calls to subscribers on non-director exchanges
within local call-charging range of the London director exchange
area were carried by tandem exchange Toll A: a subscriber would dial a prefix code, usually of three letters, followed by the number of the other subscriber on the fringe non-director exchange. Calls from fringe non-director exchanges to numbers within the director area were passed in two ways. For those to director exchanges near the area boundary adjacent to the non-director exchange, subscribers were given codes to dial, and told to follow the code with the numerical portion of the other subscriber's number. For director exchanges remote from the area boundary, the subscriber was told to dial 7, to wait for a second dialling tone, and to follow this with the whole of the other number. These calls were handled by tandem exchange Toll B, from which the second dialling tone originated. To have a second dialing tone in this way was very unusual on the PSTN in the UK, although the French PTT had a similar instruction for when their customers made international calls.
The distinction between trunk and toll became irrelevant when subscriber trunk dialling (STD
) was introduced.
Bell System
The Bell System was the American Bell Telephone Company and then, subsequently, AT&T led system which provided telephone services to much of the United States and Canada from 1877 to 1984, at various times as a monopoly. In 1984, the company was broken up into separate companies, by a U.S...
, local telephone
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
calls were flat rate
Flat rate
A flat fee, also referred to as a flat rate or a linear rate, refers to a pricing structure that charges a single fixed fee for a service, regardless of usage. Rarely, it may refer to a rate that does not vary with usage or time of use...
; i.e., included in the subscribers' fixed fees except in a few big cities, and the term toll was adopted
for long distance call
Long Distance Call
"Long Distance Call" is an episode of the American television anthology series The Twilight Zone.-Synopsis:A boy communicates with his father's European-immigrant mother, who had recently died, using a toy telephone that she gave him on his birthday before her passing. The boy, Billy, runs out in...
s because they were subject to tolls.
In the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
all calls were chargeable and the term trunk
Trunking
In modern communications, trunking is a concept by which a communications system can provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually. This is analogous to the structure of a tree with one trunk and many branches. Examples of...
was adopted for long distance calls. Initially a trunk call had to be booked in advance and an operator
Telephone operator
A telephone operator is either* a person who provides assistance to a telephone caller, usually in the placing of operator assisted telephone calls such as calls from a pay phone, collect calls , calls which are billed to a credit card, station-to-station and person-to-person calls, and certain...
would call the subscriber when the call could be put through. In 1921 the first toll exchange was opened which allowed the shorter-distance trunk calls to be connected while the subscriber waited. The name toll was probably taken from US usage.
In the London telephone area, calls to subscribers on non-director exchanges
Director telephone system
The Director System was a system which made it possible to call subscribers at other telephone exchanges without operator intervention in large multi-exchange cities, and to have a mixture of automatic and manual exchanges within these cities...
within local call-charging range of the London director exchange
Director telephone system
The Director System was a system which made it possible to call subscribers at other telephone exchanges without operator intervention in large multi-exchange cities, and to have a mixture of automatic and manual exchanges within these cities...
area were carried by tandem exchange Toll A: a subscriber would dial a prefix code, usually of three letters, followed by the number of the other subscriber on the fringe non-director exchange. Calls from fringe non-director exchanges to numbers within the director area were passed in two ways. For those to director exchanges near the area boundary adjacent to the non-director exchange, subscribers were given codes to dial, and told to follow the code with the numerical portion of the other subscriber's number. For director exchanges remote from the area boundary, the subscriber was told to dial 7, to wait for a second dialling tone, and to follow this with the whole of the other number. These calls were handled by tandem exchange Toll B, from which the second dialling tone originated. To have a second dialing tone in this way was very unusual on the PSTN in the UK, although the French PTT had a similar instruction for when their customers made international calls.
The distinction between trunk and toll became irrelevant when subscriber trunk dialling (STD
Subscriber trunk dialling
Subscriber trunk dialling is a term for a telephone system allowing subscribers to dial trunk calls without operator assistance.- Terminology :...
) was introduced.