Dial String Notation for Local, Long-Distance, and International Calls for a Dial Plan

You configure a dial plan to implement digit patterns for the types of calls that the enterprise supports—emergency, internal, local, long-distance, international, and custom—so that the system can recognize the digits of a called number that correspond to a pattern and act on it to route the call. Digits for these numbers follow conventions. Table 14 identifies conventions used for called numbers.

To enable users to dial outside the branch, dial strings include the prefix 9. Many enterprises use this notation for external calls, but not all do. Table 14 shows dial string notations and examples of them.

Table 14: Dial String Notations

Long-Distance Calls and Local Calls

International Calls

The dial string for long-distance calls is: NDD-area code-subscriber number.
For example, a SuperGear employee at the local branch in Pasadena wishes to call a customer in Boston: 9–1–617–936–1234.
The dial string for local calls is: Subscriber Number
For example, a SuperGear employee at the Pasadena branch wants to make a local call outside the branch: 9–336–2345

The dial string for international calls is: PSTN access code — IDD — country code—area code—subscriber number.

For example, a SuperGear employee in the United States wishes to call the main number at the Toyabi TopNoch Corporation in Kochi, Japan: 9–011–81–90–555–1212

National direct dialing (NDD), also referred to as the national prefix, is the access code used to make calls within a country from one city or area to another.

The NDD for the United States is 1.
The NDD for Japan is 0.

International direct dialing (IDD), which is also referred to as the international prefix, is the access code used to dial out of a country to another country.

The IDD for the United States is 011.
The IDD for Japan differs across providers. For Japan Telcom, it is 0041.

Note: For a dial pan in the United States, you do not need to use the Japanese IDD. For a dial plan in Japan, you use the IDD for the service provider you are using. You do not need to use the United States IDD.

Area code, which usually indicates geographical areas within a country, is required for calls outside the local area–that is, non-local calls. For mobile phones, it is not tied to a geographical area.

For New York City, New York, it is 212.
For Pasadena, California, it is 626.

Country code is the national prefix used when dialing to one country from another.

For the United States, it is 1.
For Japan, it is 81.

Local–that is, the subscriber number–for individual telephones. The first few digits represent smaller geographical areas, or individual telephone exchanges, or a network provider.

For example, for Pasadena, California, the first part of the subscriber number is 398. The following four digits represent the individual telephone. A complete subscriber number might be 398–5555.