Direct Distance Dialing

Direct distance dialing (DDD) or direct dial is a telecommunications term for a network-provided service feature in which a call originator may, without operator assistance, call any other user outside the local calling area. DDD requires more digits in the number dialed than are required for calling within the local area or area code. DDD also extends beyond the boundaries of national public telephone network, in which case it is called international direct dialing or international direct distance dialing (IDDD).

DDD is a North American Numbering Plan term considered obsolete since completing a call in any manner other than direct dialing became rare. In the United Kingdom and other parts of the Commonwealth of Nations, the equivalent terms are or were "STD", for subscriber trunk dialing, and "ISD" for international subscriber trunk dialing.

Read more about Direct Distance Dialing:  History, Hardware, IDDD

Famous quotes containing the words direct, distance and/or dialing:

    England and France, Spain and Portugal, Gold Coast and Slave Coast, all front on this private sea; but no bark from them has ventured out of sight of land, though it is without doubt the direct way to India.
    Henry David Thoreau (1817–1862)

    Midway the lake we took on board two manly-looking middle-aged men.... I talked with one of them, telling him that I had come all this distance partly to see where the white pine, the Eastern stuff of which our houses are built, grew, but that on this and a previous excursion into another part of Maine I had found it a scarce tree; and I asked him where I must look for it. With a smile, he answered that he could hardly tell me.
    Henry David Thoreau (1817–1862)

    Although I will inherit darkness
    I will keep dialing left to right.
    I will struggle like a surgeon.
    I will call quickly for the glare of the moon.
    I will even dial milk.
    Anne Sexton (1928–1974)