AT&T MERLIN LEGEND Release 4.0 Feature Reference page 74

Feature Reference
NOTE:
If a voice call is queued for callback on a digital trunk pool, it can get stuck in
an infinite loop of queuing. The caller hears a continuous stutter tone and
cannot get rid of it. To avoid this situation, be certain to correctly program the
voice and/or data capabilities of pools of PRI and BRI facilities in the ARS
tables.
Any remaining eligible routes are scanned from the beginning of the list. The
first eligible route that is not busy is selected. If all eligible routes are busy, the
user hears fast busy and can use Callback to queue the call for the first route
only.
NOTE:
Emergency numbers must be on an Allowed List to be called from a
call-restricted extension.
Considerations and Constraints
ARS restrictions (FRLs) operate independently of dial-access-to-pool
restrictions, providing greater flexibility in assigning the type of usage an
extension is allowed.
The international dialing code (011) can be included in any fully programmable
table. If this is done, calls beginning with 011 are routed according to the table
on which 011 is entered, and not according to the Dial 0 table.
The wild card character (Pause) cannot be used in system programming to
enter area codes and/or exchanges in ARS tables.
Calls made to the equal access code (10 xxx ) are always routed immediately
over the main pool, regardless of whether or not they appear in other ARS
tables.
People who are restricted from using a particular ARS route hear a high-low
error tone indicating the call cannot be completed.
Even if the local telephone company does not require it, callers must dial
before any 10-digit telephone number to allow determination of whether a call is
toll or local. If the 1 is not required by the local central office, the system may be
programmed to ignore it.
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Automatic Route Selection