that paved the way for Direct Distance Dialing (DDD) by telephone service subscribers. Operator Toll Dialing was developed in the early 1940s for regional...

intermediary telephone operators and reducing cost. It was initially designed and implemented for Operator Toll Dialing, in which operators at the origination...

originating toll operators to dial calls directly to the destination. This system was known as Operator Toll Dialing. Operator Toll Dialing required a...

service to direct distance dialing is subscriber trunk dialing (STD), and ISD for international subscriber trunk dialing.[citation needed] Queen Elizabeth...

A toll-free number is identified by a dialing prefix similar to an area code. The specific service access varies by country. The features of toll-free...

the planning for a nationwide numbering plan for Operator Toll Dialing and direct distance dialing (DDD) in the Bell System in the United States in the...

Europe to automating switching on the toll networks in their respective countries (initially for Operator Toll Dialing). Thus, when TAT-1 was opened for service...

Seven-digit dialing is a telephone dialing procedure customary in some territories of the North American Numbering Plan (NANP) for dialing telephone numbers...

the fifth regional dial switching center for Operator Toll Dialing in the nation, which set the stage for direct distance dialing by customers in the...

(AT&T) created the first nationwide telephone numbering plan for Operator Toll Dialing in 1947 to automate and speed the connection of long-distance calls...

(AT&T) created the first nationwide telephone numbering plan for Operator Toll Dialing in 1947 to automate and speed the connection of long-distance calls...

participation in nationwide operator and customer toll dialing. They supersede the Notes on "Nationwide Operator Toll Dialing" which were furnished to the...

(AT&T) established the first nationwide telephone numbering plan for Operator Toll Dialing in October 1947, Nassau and Suffolk counties, the lower Hudson Valley...

(AT&T) introduced the first nationwide telephone numbering plan for Operator Toll Dialing in 1947, the state of California was divided into three numbering...

automated system called Nationwide Operator Toll Dialing that was begun in 1943, which eventually led to Direct Distance Dialing (DDD) within the framework of...

comprehensive telephone numbering plan for the North American continent for Operator Toll Dialing. This was an effort to speed up the connection time of long-distance...

plans were changed to the 2L-5N system to prepare for nationwide Operator Toll Dialing. For example, under this system, a well-known number in New York...

first configuration of a nationwide telephone numbering plan for Operator Toll Dialing, which designated the state of Maryland as a numbering plan area...

to transition to 10-digit dialing by October 24, 2021. Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone...

area, and assigned area code 305 as a destination routing code for Operator Toll Dialing. The southwest portion was split off in 1953 with area code 813...

assigned area code 905. A permissive dialing, during which dialing of either 416 or 905 was acceptable in a dialed number terminating in the new NPA, was...

service until 1949. In preparation for Operator Toll Dialing, the precursor to customer DDD (Direct Distance Dialling), cities throughout the country converted...

(AT&T) published the first nationwide telephone numbering plan for Operator Toll Dialing in 1947, Massachusetts was divided into two numbering plan areas...

permissive dialing period was conducted from April 21 to October 20 during which calls could be initiated by seven- or ten-digit dialing. Ten-digit dialing also...

configuration of the first nationwide telephone numbering plan for Operator Toll Dialing in 1947. Area code 617 was assigned to the eastern two-thirds of...

extreme northeast) Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone Magazine. 26 (4): 181. Retrieved...

Pennsylvania area codes Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone Magazine. 26 (4): 181. Retrieved...

a unique code for each area, to speed the connection times for operator toll dialing. The state of Florida was a single numbering plan area with area...

created a universal North American telephone numbering plan for Operator Toll Dialing in 1947, Missouri was divided into two numbering plan areas (NPAs)...

County Yamhill County Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone Magazine. 26 (4): 181. Retrieved...