Telephone Numbering Plan - Standards

Standards

Although the International Telecommunication Union (ITU) has attempted to promote common standards among nation states, numbering plans take different formats in different parts of the world. For example, the ITU recommends that member states adopt 00 as their international access code. However, as these recommendations are not binding on member states, some have not, such as the United States, Canada, and other countries and territories participating in the North American Numbering Plan.

The international numbering plan establishes country codes, that is, area codes that denote nations or groups of nations. The E.164 standard regulates country codes at the international level and sets a maximum length limit on a full international phone number (15 digits). However, it is each country's responsibility to define the numbering within its own network. As a result, regional area codes may be:

  • A fixed length, e.g., three digits in the United States and Canada; two digits in Brazil; one digit in Australia and New Zealand,
  • A variable length, e.g., between 2 and 5 in Germany, Argentina, United Kingdom and in Austria; between 1 and 5 in Japan; 1 or 2 in Syria and Peru, or
  • Incorporated into the subscriber's number, as is the case in many countries, such as Spain or Norway. This is known as a "closed" telephone numbering plan. In some cases a trunk code (usually 0) must still be dialed, as in Belgium, Italy, Switzerland, South Africa and some locations within the NANP. Hong Kong used to have 1-digit area codes. They were incorporated into the subscriber's numbers back into the 1990s. No trunk code is required.

Read more about this topic:  Telephone Numbering Plan

Famous quotes containing the word standards:

    With his brows knit, his mind made up, his will resolved and resistless, he advances, crashing his way through the host of weak, half-formed, dilettante opinions, honest and dishonest ways of thinking, with their standards raised, sentimentalities and conjectures, and tramples them all into dust. See how he prevails; you don’t even hear the groans of the wounded and dying.
    Henry David Thoreau (1817–1862)

    To arrive at a just estimate of a renowned man’s character one must judge it by the standards of his time, not ours.
    Mark Twain [Samuel Langhorne Clemens] (1835–1910)

    There are ... two minimum conditions necessary and sufficient for the existence of a legal system. On the one hand those rules of behavior which are valid according to the system’s ultimate criteria of validity must be generally obeyed, and on the other hand, its rules of recognition specifying the criteria of legal validity and its rules of change and adjudication must be effectively accepted as common public standards of official behavior by its officials.
    —H.L.A. (Herbert Lionel Adolphus)