AT&T MERLIN LEGEND Release 4.0 Feature Reference page 65

Feature Reference
Description
Automatic Route Selection (ARS) is available only in Hybrid/PBX mode. ARS
allows outgoing calls to be dynamically routed over selected trunk facilities after
dialing an ARS access code (usually a
least expensive route for each call.
Programmable lists, called tables , indicate the desired routes (line/trunk
facilities) for specified area codes and/or exchanges. There is a different ARS
table for each type of call (local, toll, special number, etc.). The tables are
chosen according to the telephone number digits that are dialed by the user.
Each ARS table has a particular trunk pool that it routes calls to.
A table contains some or all of the following types of information:
Table Type. Indicates how to interpret the information in the table. Table
types are Area Code, Local Exchange, 6-Digit, 1 + 7, Dial 0, Special
Numbers (N11), Default Toll, and Default Local. Details for each table
type are discussed later in this section.
Digit Strings. 3-digit entries in the table, typically area codes or
exchanges. Dialed digits are compared to the stored digits. A match
should occur in only one table and cause selection of the routes
specified in that table.
Subpattern. An array of up to six routes. There are two subpatterns for all
tables except the Special Numbers (N11) and Dial 0 tables. The
subpattern selected depends on the time of day that the call is made,
and the start time associated with each subpattern. (The start time for
Subpattern A is specified as the stop time for Subpattern B.)
The Special Numbers (N11) Table always uses the main pool and thus
has neither subpatterns nor routes. The Dial 0 Table has no subpatterns
and only one route.
Routes. A structure that defines possible trunks to be used in a preferred
order, usually based on lowest cost and the telephone user's privilege
level or Facility Restriction Level (FRL). Routes cannot be programmed
for the Special Numbers (N11) Table. A route contains the following types
of information.
Pool. A group of trunks that are to be used for this route. A pool must
be programmed before any other route information.
Facility Restriction Level (FRL). A value from 0 to 6 associated with
the route. (0 is the least restrictive and 6 is the most restrictive value
for routes.) In order to use the route, a caller (according to extension
or remote access barrier code/trunk) must have an FRL that is equal
to or greater than the FRL of a route.
). This enables the system to select the
Automatic Route Selection
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