Lucent Technologies MERLIN LEGEND Release 5.0 Maintenance And Troubleshooting Manual page 296

MERLIN LEGEND Communications System Release 5.0
Maintenance and Troubleshooting 555-650-140
Customer Support Information
Toll Fraud Prevention
If the Automated Attendant prompts callers to use Remote Call
Forwarding (RCF) to reach an outside telephone number, the system
may be susceptible to toll fraud. An example of this application is a menu
or Submenu that says, "To reach our answering service, select prompt
number 5," and transfers a caller to an external telephone number.
Remote Call Forwarding can only be used securely when the central
office provides "reliable disconnect" (sometimes referred to as forward
disconnect or disconnect supervision), which guarantees that the central
office will not return a dial tone after the called party hangs up. In most
cases, the central office facility is a loop-start line/trunk which does not
provide reliable disconnect. When loop-start lines/trunks are used, if the
calling party stays on the line, the central office will return a dial tone at
the conclusion of the call, enabling the caller to place another call as if it
were being placed from your company. Ground-start trunks provide
reliable disconnect and should be used whenever possible.
Preventive Measures
Take the following preventive measures to limit the risk of unauthorized use of the
Automated Attendant feature by hackers:
Do not use Automated Attendant prompts for Automatic Route Selection
(ARS) Codes or Pooled Facility Codes.
Assign all unused Automated Attendant Selector Codes to zero, so that
attempts to dial these will be routed to the system attendant.
If Remote Call Forwarding (RCF) is required, MERLIN LEGEND
Communications System owners should coordinate with their Lucent
Technologies Account Team or authorized dealer to verify the type of
central office facility used for RCF. If it is a ground-start line/trunk, or if it
is a loop-start line/trunk and central office reliable disconnect can be
ensured, then nothing else needs to be done.
Issue 1
June 1997
Page A-20