AT&T MERLIN LEGEND Release 4.0 Feature Reference page 35

Feature Reference
Star Codes and Allowed/Disallowed Lists
In some instances, after dialing a star code (a star digit followed by a two or
three digit number) the central office provides a second dial tone as a prompt
for the dialer to enter more digits. In most cases this second dial tone is
immediate. However, in cases when the second dial tone is delayed, calls can
be misrouted or dishonest users might be able to circumvent communications
system dialing restrictions.
In Release 3.1 and later, the system administrator can enter the star digit (*) in
Allowed List and Disallowed List entries. The communications system can be
programmed with a delay period (Second Dial Tone Timer) during which no
dialing is allowed (in order to let the central office dial tone return). If dialing is
attempted, the call is treated as though it had violated calling restrictions and is
not completed.
The star codes that are recognized by the system are as follows:
2-digit codes: (00-19,40-99)
3-digit codes: (200-399)
Restrictions are reset after leading star codes. This means that any star codes
that are not included in an Allowed or Disallowed List are not considered. The
digits that follow the star code are then compared again to the lists. If a caller
dials *67280, Allowed/Disallowed Lists acts as if 280 were dialed. Star codes do
not need to be placed into an Allowed or Disallowed List in this case to restrict
calls to specific exchanges or Area Codes.
The programmed delay is also activated when the rotary telephone equivalent of
star codes is dialed (for example, 1170). Multiple leading star codes (such as
*67*70) are also handled by the system, since the dialed number is checked
against Allowed and Disallowed Lists after each star code is detected.
Following are examples of how to set table entries to achieve specific results:
Disallow calls preceded by *67, but allow all other calls: Enter *67 as a
Disallowed List entry.
Disallow calls preceded by all star codes, but allow all other calls: Enter *
as a Disallowed List entry.
Disallow calls preceded by *67, or by *69 but allow all other calls: Enter
*67 as a Disallowed List entry and enter *69 as a separate entry.
Disallow calls preceded by *67, calls to 900 numbers and 411 but allow
all other calls: Enter *67, 900, and 411 as separate Disallowed List
entries.
Allowed/Disallowed Lists
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