3Com SuperStack 3 NBX, Administrator'S Manual

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Dial Plan Pretranslators 41
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” later in this chapter.
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 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
extension range. “Sample Solutions Using Dial Plan Configuration File
Commands” later in this chapter 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.