Instruction manual

Tools that restrict unauthorized outgoing calls
Issue 9 May 2003
5-21
Recall signaling (switchhook flash)
Recall signaling allows analog station users to place a call on hold and consult
with another party or activate a feature. After consulting with the third party, the
user can conference the third party with the original party by another recall signal,
or return to the original party by pressing
Recall twice or by flashing the
switchhook twice.
However, hackers have been able to activate recall signaling to gain second dial
tone and conference incoming and outgoing paths together. To prevent this,
administer switchhook flash to
n (administered by means of the Add or Change
Station screen) for FAX machines and modems.
Attendant - controlled voice terminals
When telephones are located in easily-accessible locations (such as lobbies) that
do not provide protection against abuse, you can assign them to an
attendant-controlled voice terminal group. Calls from the group can be connected
to an attendant who screens the calls. As part of the night shut down procedure,
the attendant can activate outgoing call restrictions on the group.
Restrictions — individual and group-controlled
(Communication Manager, MultiVantage
Software, DEFINITY ECS, DEFINITY G1,
G3, and System 75)
For Communication Manager, MultiVantage™ Software, DEFINITY ECS,
DEFINITY G1, G3, and System 75, individual and group-controlled restrictions
allow an attendant or voice terminal user with console permission to activate and
deactivate the following restrictions for an individual terminal or a group of voice
terminals:
■ Outward — The voice terminals cannot be used for placing calls to the
public network. Such call attempts receive intercept tone.
■ Total — The voice terminals cannot be used for placing or receiving calls.
DID calls are routed to the attendant or a recorded announcement. All
other calls receive intercept tone. As an exception, the following call types
are allowed: calls to a remote access extension, terminating trunk
transmission tests, and emergency access to attendant calls.
■ Station-to-station — The voice terminal cannot receive or place
station-to-station calls. Such call attempts receive intercept tone.
■ Termination — The voice terminal cannot receive any calls. Incoming calls
are routed to the attendant, are directed via call coverage, or receive
intercept treatment.
All voice terminals with the same COR are affected by a group restriction. When a
call is placed, both the individual and group restrictions are checked.