42 CHAPTER 2: DIAL PLAN
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 116 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 38 and “Least Cost Routing Dial
Plan Table” on page39.
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.