Verilink 8100A (34-00237) Product Manual - Manual (Page 305)

A p p l i c a t i o n s N o t e s D-13
| 00 | Long distance operator |
| xxxx | Local extension number |
| 8xxxxxxx | Local number |
| #xxxxxxx | Shortcut to local number at|
| | other corporate sites |
| *xx | Star services |
| 91xxxxxxxxxx | Long distance number |
| 9011 + up to 15 digits| International number |
------------------------------------------------------
The solution to this problem is to have the Call Agent load the gateway with a
digit map that may correspond to the dial plan. This digit map is expressed
using a syntax derived from the Unix system command, egrep. For example,
the dial plan described above results in the following digit map:
(0T|00T|[1-7]xxx|8xxxxxxx|#xxxxxxx|*xx|91xxxxxxxxxx|
9011x.T)
The formal syntax of the digit map is described by the DigitMap rule in the
formal syntax description of the protocol
− support for basic digit map letters
is REQUIRED while support for extension digit map letters is OPTIONAL. A
gateway receiving a digit map with an extension digit map letter not
supported SHOULD return error code 537 (unknown digit map extension).
A digit map, according to this syntax, is defined either by a (case insensitive)
"string" or by a list of strings. Each string in the list is an alternative
numbering scheme, specified either as a set of digits or timers, or as an
expression over which the gateway will attempt to find a shortest possible
match. The following constructs can be used in each numbering scheme:
* Digit: A digit from "0" to "9".
* Timer: The symbol "T" matching a timer expiry.
* DTMF: A digit, a timer, or one of the symbols "A",
"B", "C", "D", "#", or "*". Extensions may be defined.
* Wildcard: The symbol "x" which matches any digit ("0"
to "9").
* Range: One or more DTMF symbols enclosed between
square brackets ("[" and "]").
* Subrange: Two digits separated by hyphen ("-") which
matches any digit between and including the two. The
subrange construct can only be used inside a range
construct, i.e., between "[" and "]".
* Position: A period (".") which matches an arbitrary
number, including zero, of occurrences of the preceding
construct.
A gateway that detects events to be matched against a digit map MUST
do the following:
1 Add the event code as a token to the end of an internal state variable for
the endpoint called the "current dial string".
2 Apply the current dial string to the digit map table, attempting a match to
each expression in the digit map.