El Procedimiento Abreviado

The system uses pretranslators to modify digit sequences of incoming or outgoing calls. On incoming calls, pretranslators can map the entire dialed number (including area code) to an internal extension number. For example, an external party dials 978-555-0101 to reach the person on extension 101. Pretranslators ensure that the proper digits are mapped to the correct extension number.

For more information, see:

■ Pretranslators for Incoming Calls on page 43

■ Pretranslators for Certain Outgoing Calls on page 44

A typical pretranslator function involves mapping incoming DDI/DID telephone calls to internal extension numbers.

Dial Plan Pretranslators 43

Example: Say that the DDI/DID (Direct Inward Dial/Direct Dial Inward) telephone numbers range from 508-555-4200 through 508-555-4299. The telephone company sends you the last 4 digits of the total telephone number. Internally, you want to use extensions 2000 through 2099. You can define a pretranslator to:

■ Remove (stripLead) the first two digits of the incoming 4-digit

sequence.

■ Add (prepend) the digits 20 in front of the remaining 2 digits.

See “Managing Dial Plan Pretranslators” on page 69 for detailed information and examples on creating and managing dial plan pretranslators.

Pretranslators for Incoming Calls

For incoming calls, pretranslation reformats the dialed number before it is passed to the Incoming dial plan table (Table ID 2). See “Incoming Dial Plan Table” on page 40. For information on how to properly handle caller ID information over incoming VTL calls, see “Creating a Pretranslator for VTL Calls” on page 70.

Incoming Pretranslator Example 1

If, for an incoming telephone call, the telephone company passes you 4-digit numbers from 6100 through 6199, the system can use a

pretranslator to remove the first digit; the remaining 3 digits can then be used as internal extension numbers in a 3-digit dial plan. Tell the system which pretranslations that you want to perform by defining digit manipulation operations (append, prepend, replace, stripLead, or stripTrail) within the PreTranslator section of the dial plan configuration file.

Incoming Pretranslator Example 2

Assume the telephone company passes 10-digit numbers to the system for each incoming telephone call (for example, numbers in the range 4567-89-3000 to 4567-89-3500). If the system uses 4-digit extensions in the range 2000 to 2500, you could pass an incoming 10-digit number such as 4567-89-3210 to extension 2210.

This strategy requires two pretranslation operations: The first operation performs a stripLead operation to remove the initial 7 digits, leaving 210. The second operation prepends the number 2 in front of the remaining 3 digits. The result is 2210, which matches an extension within the

Commands” on page 124 shows how to accomplish this pretranslation using the dial plan configuration file.

Each device can specify only one DDI/DID pretranslator and one CLIP pretranslator. To create or modify a pretranslator, you either edit a dial plan configuration file and import it, or use the NBX NetSet utility and modify an existing dial plan configuration file.

The system performs operations in ascending order of operation ID. Operations are both sequential and cumulative.

You can also use pretranslators with virtual tie lines to link multiple NBX systems. Incoming calls within a defined numeric range arrive at the first system, are modified through digit manipulation operations, and are then routed to a tie line connected to a second system.

Each sample dial plan that is shipped with the system includes a default pretranslator.

Pretranslator Example 3

Assume that the telephone company passes 4-digit numbers to the system for each incoming telephone call (for example, numbers in the range 5200 through 5300). If the system uses 3-digit extensions in the range 200 through 300, you could define a single pretranslation

operation to stripLead (remove) the first digit, for instance, the number 5 from an incoming number such as 5278, and pass the call to extension 278. “Sample Solutions Using Dial Plan Configuration File Commands”

on page 124 shows how to accomplish this pretranslation using the dial plan configuration file.

Pretranslators for Certain Outgoing Calls

On outgoing calls using an ISDN PRI card, pretranslators allow the external called party to identify the full number of the internal calling party, including the area code. For example, if the person on extension 101 within a company calls an external number, the caller’s entire number is displayed to the called party when Calling Line ID Presentation (CLIP) pretranslators are used. Pretranslation reformats the outgoing dialed number before it is passed to the Internal dial plan table (Table ID 1) or possibly the Least Cost Routing table (Table ID 3). For more information, see “Internal Dial Plan Table” on page 40 and “Least Cost Routing Dial Plan Table” on page 41.

Dial Plan Pretranslators 45

Example: If the DDI/DID telephone numbers range from 508-555-4200 through 508-555-4299, internally, you dial extensions from 2000 through 2099 to reach another internal telephone.

When you place a call to an external telephone number, the system can use these pretranslator steps to create the full 10-digit number:

1 Remove (stripLead) the first two digits (20) from the internal extension number of the telephone making the call.

2 Add (prepend) the digit sequence 50855542 to the two remaining digits, creating the full DDI/DID telephone number.

3 Pass the full number to the telephone company.

Example: To transmit Calling Line ID Presentation (CLIP) information on outgoing calls, you can define a pretranslator that transforms internal extensions into full telephone numbers (the numbers that someone external to the company uses to dial in). Assume that you are using telephone extension numbers from 1000 to 1099 and that only the last two digits match the DDI/DID numbers that are assigned to the company. You can define a pretranslator to remove (stripLead) the first two digits from the internal extension number and add (prepend) the appropriate digit string. This pretranslator constructs the full telephone number. Example: If you use two different long-distance carriers at different times of the day to save costs, you can prepend different digit sequences to the outgoing dialed number to select which carrier that you want. If you prepend 1010321 between the time the business opens and 3:00 p.m., you select one long-distance carrier. If you prepend 1010220 from 3:00 p.m. until the next time the business opens (including weekends), you select the other carrier and obtain a lower rate.

To tell the system which outgoing pretranslations that you want to perform, you define digit manipulation operations (append, prepend, replace, stripLead, or stripTrail) in the Routes section of the dial plan configuration file. You can define these commands for both destination routes and timed routes. For more information on configuring

Managing