27.1 Dialing Plan Features
This section describes various dialing plan features supported by the device.
27.1.1 Digit Mapping
Digit map pattern rules are used for Tel-to-IP ISDN overlap dialing (by setting the
ISDNRxOverlap parameter to 1) to reduce the dialing period (for digital interface). For more
information on digit maps for ISDN overlapping, see ISDN Overlap Dialing on page 292.
The device collects digits until a match is found in the user-defined digit pattern (e.g., for
closed numbering schemes). The device stops collecting digits and starts sending the
digits (collected number) when any one of the following scenarios occur:
Maximum number of digits is received. You can define (using the MaxDigits
parameter) the maximum number of collected destination number digits that can be
received (i.e., dialed) from the Tel side by the device. When the number of collected
digits reaches the maximum (or a digit map pattern is matched), the device uses these
digits for the called destination number.
Inter-digit timeout expires (e.g., for open numbering schemes). This is defined using
the TimeBetweenDigits parameter. This is the time that the device waits between each
received digit. When this inter-digit timeout expires, the device uses the collected
digits to dial the called destination number.
Digit string (i.e., dialed number) matches one of the patterns defined in the digit map.
Digit map (pattern) rules are defined using the DigitMapping parameter. The digit map
pattern can contain up to 52 options (rules), each separated by a vertical bar ("|"). The
maximum length of the entire digit pattern is 152 characters. The available notations are
described in the table below:
Digit Map Pattern Notations
Notation Description
[n-m]
Range of numbers (not letters).
.
(single dot) Repeat digits until next notation (e.g., T).
x
Any single digit.
T
Dial timeout (configured by the TimeBetweenDigits parameter).
S
Short timer (configured by the TimeBetweenDigits parameter; default is
two seconds) that can be used when a specific rule is defined after a
more general rule. For example, if the digit map is 99|998, then the digit
collection is terminated after the first two 9 digits are received. Therefore,
the second rule of 998 can never be matched. But when the digit map is
99s|998, then after dialing the first two 9 digits, the device waits another
two seconds within which the caller can enter the digit 8.
Below is an example of a digit map pattern containing eight rules:
DigitMapping = 11xS|00[1-
7]xxx|8xxxxxxx|#xxxxxxx|*xx|91xxxxxxxxxx|9011x|xx.T
In the example, the rule "00[1-7]xxx" denotes dialed numbers that begin with 00, and then
any digit from 1 through 7, followed by three digits (of any number). Once the device
receives these digits, it does not wait for additional digits, but starts sending the collected
digits (dialed number) immediately.
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