Technical information

System 25
Issue 7 June 2001
5-63
System 25
This section provides information on protecting the System 25.
Additional security measures are required to protect adjunct equipment.
 Chapter 6 contains security measures to protect the attached voice
messaging system. For general security measures, refer to ‘‘Protecting
Voice Messaging Systems’’ on page 6-2. For product-specific security
measures, refer to ‘‘System 25’’ on page 6-59.
 Chapter 7 contains security measures to protect the Automated Attendant
feature of your communications system. See ‘‘System 25’’ on page 7-22.
System 25 allows trunk-to-trunk transfer capability, increasing the opportunities
for toll fraud. However, trunk-to-trunk transfers on loop-start trunks are not allowed
unless the switch is administered to allow it. A fast busy signal indicates that the
transfer is not allowed. Do not allow trunk-to-trunk transfers on loop start trunks
unless there is a business need for it. This may be administered from the system
administration menu.
For R3V3, international calls (or international calls to selected countries) can be
disallowed from a toll restricted station, and toll restricted stations can be blocked
from using Interexchange Carrier Codes (IXCs) to make domestic or international
direct dialed calls. Also, unless a trunk pool is administered for “Originating Line
Screening,” toll restricted stations cannot make operator-assisted calls.
To further reduce the system’s vulnerability to toll fraud, outward restrict the
tip/ring port to which the Remote Maintenance Device is connected.
Protecting Remote Access
The Remote Access feature allows users to call into System 25 from a remote
location (for example, a satellite office, or while traveling) and use the system to
make calls. However, unauthorized persons might learn the Remote Access
telephone number and password (barrier access code), call into the system, and
make long distance calls.
System 25 allows up to 16 different barrier access codes and one Remote
Maintenance barrier access code for use with the Remote Access feature. Except
for R3V3, barrier access codes have a 5-digit maximum. R3V3 allows up to 15
characters, including the digits 0 to 9, #, and *. Also for R3V3, an alarm is
generated at the attendant console if an invalid barrier access code is entered.
For greater security, always use the maximum available digits when assigning
barrier access codes.
The following security measures assist you in managing the Remote Access
feature to help prevent unauthorized use.