Dialing Rules and Canonical Address Format

Applies To: Windows Server 2008

Telephony API (TAPI) allows you to configure dialing rules for all telephony programs. If you run a TAPI-supported program before configuring dialing, the program normally prompts you for the minimum information required for dialing. To completely configure dialing rules on a computer, use Phone and Modem Options in Control Panel, as described in this topic.

The following aspects of TAPI are discussed in this section:

• Telephone and modem dialing rules

• Canonical address format for phone numbers

Telephone and modem dialing rules

A dial location is the set of parameters that is used to analyze telephone numbers and determine the correct sequence of numbers to dial. You can create as many dial locations as you need for different dialing requirements.

A dial location can correspond to a geographic location, such as an office or hotel room, where you need to include codes for dialing outside of the company or building. If your work takes you to different cities, countries, or regions, you can create a dial location for each area, city, or country/region code.

A dial location can also be created for dialing rules that are not necessarily associated with a geographic location. For example, you can create different dialing rules for different company accounts, calling cards, or long distance services.

Dial location information includes:

• Name

• Country or region

• Area (or city) code

• Dialing rules

• Area code rules

• Calling card information

Naming and using dialing locations

Dialing locations can be named anything that is helpful for remembering them later. The default dialing location is the location selected in the Phone and Modem Options dialog box. Many telephony programs allow you to select a different dialing location before dialing. When a telephony program dials a long distance number, it uses the dialing information provided by the selected dialing location to complete the connection.

The available dialing locations are listed on the Dialing Rules tab of Phone and Modem Options in Control Panel. On this tab, you can select the default dialing location, create a new dialing location, or edit any existing dialing location. To create a new dialing location, see "Create a New Dialing Location" in the Network and Sharing Center Operations Guide (https://go.microsoft.com/fwlink/?LinkId=108871). If you want to edit an existing dial location, see "Change Dialing Properties for a Location" in the Network and Sharing Center Operations Guide (https://go.microsoft.com/fwlink/?LinkId=108872).

General dialing location rules

General dialing location rules specify the name of a location, the country or region, and the local area code. They also enable you to access outside lines from a PBX for local and long distance calls, disable call waiting (so incoming calls do not interrupt connections), and specify either tone or pulse dialing.

The default rules for dialing local, long distance, and international calls are determined by the country or region that you have selected. Dialing rules specify the long distance operator and international prefix that is dialed before domestic long distance or international phone numbers.

Area code rules

Area code rules enable you to change the dialing patterns for calls to numbers in the same country or region, as described in "Specify Area Code Rules" in the Network and Sharing Center Operations Guide (https://go.microsoft.com/fwlink/?LinkId=108873). The default area code rule for numbers in another area code often requires the program to dial the long distance operator, the area or city code, and then the phone number. For numbers in the same area code, the program dials only the subscriber's phone number. The default rules are shown in the following table.

Digits dialed in each of these categories may be different for different countries, regions, or locations.

Use area code rules to specify any of the following exceptions to the default rules:

If you use a long distance operator different from the country/region default for all area codes, it is much easier to use a calling card for the dialing location instead of creating an area code rule for every area or city code that you dial. For more information, see "Calling cards" in this topic.

Specifying more than one rule for an area code

When different prefixes in an area code are dialed differently, you can specify more than one rule for the area code. Area code rules are applied from top to bottom in the list. If two rules apply to a particular prefix in an area code, the last rule in the list determines the dialing pattern for that prefix.

When you create a new area code rule, it is added to the bottom of the list. To apply multiple rules correctly then, create area code rules in this order:

1. Any default rule that should apply to all unspecified prefixes. (In this case, use the Include all the prefixes within this area code option). This rule should appear at the top of the list.

2. Area code rules that list specific prefixes. (Use the Include only the prefixes in the list below option).

Most prefixes in an area code follow the default dialing patterns shown here:

When most prefixes in an area code do not follow the default dialing patterns, create one rule to specify the new default dialing pattern for the area code and create another rule to specify the few exceptions. This is easier than just creating one area code rule that lists the bulk of prefixes for an area code.

For example, suppose you dial most numbers in an area code in the following format:

(AreaOrCityCode) Prefix-SubscriberNumber

but three prefixes are dialed in this format:

1 (AreaOrCityCode) Prefix-SubscriberNumber

First, create an area code rule that applies to all prefixes in the area code and, in that rule under Rules, select only the Include the area code check box. This creates the default rule for the area code. It will apply to all the prefixes that are not specified by the second rule in the list.

Second, create an area code rule that lists the three prefixes that follow the second dialing pattern. In that rule under Rules, select both the Dial check box (confirm that the adjacent text box says 1) and the Include the area code check box. This creates a rule that applies only to the three prefixes and should appear second in the list.

Calling cards

A dialing location can use a calling card to specify the sequence of numbers to be dialed for a particular calling card or long distance service. You can also choose to use a calling card to specify a long distance operator or international operator different from the default operator for a country or region.

A calling card records the calling card number and any personal identification number (PIN). It defines the access numbers and dialing steps for local, long distance, and international calls. After you create a new calling card, you can use it with any dial location. To create or use a calling card, see "Create a New Calling Card" (https://go.microsoft.com/fwlink/?LinkId=108864) or "Use a Calling Card to Dial Long Distance" (https://go.microsoft.com/fwlink/?LinkId=108868)in the Network and Sharing Center Operations Guide.

If you use two or more long distance services with different access numbers, you can create a calling card for each service and a different dial location to use each calling card. Telephony programs typically permit you to change the dial location before dialing a number. When you dial a number, select the dial location that corresponds to the long distance service that you want to use.

Specify a long distance carrier

The long distance carrier number, also called the long distance operator, is dialed before the area code or country/region code to dial domestic or international long distance calls. The country/region selection for a dial location usually enables programs to dial the correct long distance carrier numbers for domestic and international calls. If your long distance carrier is not accessed with the default numbers for the country/region selection, see "Specify a Long Distance Carrier" in the Network and Sharing Center Operations Guide (https://go.microsoft.com/fwlink/?LinkId=108862).

Canonical address format for phone numbers

The canonical address format is a universal phone number format recognized by Windows Telephony. The format explicitly identifies the components of a phone number, which TAPI translates according to a country or region's dialing rules. The canonical address format is:

**+**Country/RegionCode **(AreaCode)**SubscriberNumber

For example, this is how you would enter a number for a subscriber in the United States of America in canonical address format:

+1 (425) 555-1212

Some address book programs store numbers in canonical address format. If your computer is not dialing a number correctly, try saving or entering the number in this format.

• +

  Indicates that the number is in canonical address format.

• Country/RegionCode

  The standard country/region code that identifies the country or region for a phone number. This contains one or more digits from 0 through 9. The country/region code is delimited by the space that follows it.

• (AreaCode)

  The area or city code for the phone number. This can contain one or more digits from 0 through 9. The area or city code is delimited by parentheses. This component is omitted for countries/regions that do not use area or city codes.

• SubscriberNumber

  The number for a phone subscriber. This contains one or more digits from 0 to 9, formatting characters, or the dialing control characters:

  A a B b C c D d P p T t W w * # ! @ $ ? ,

  The subscriber number should not contain the following characters:

  ( ) ^

  Formatting characters in the subscriber numbers are normally spaces, periods, and dashes. Use formatting characters to make a phone number easier to read. They do not affect dialing, because TAPI discards them.

Additional references

• Network and Sharing Center Functionality and Navigation

• Network Location Types

• Sharing and Discovery

• Network Diagnostics Framework

• Network Map

• How the Network and Sharing Center Works