Lucent Technologies BCS Products Security Handbook

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-11 Security Goals Tables 
2
Prevent 
unauthorized 
outgoing calls 
(continued)Restrict phones 
from making 
outbound callsAttendant-
Controlled
voice terminals
(G2 and System 85 
only)Place phones in 
attendant- 
controlled group
Limit outgoing calls FRLs Restrict tie trunk 
usage
Deny access to 
AAR/ARS/WCR
Authorization 
codesSet to maximum 
length 
Set FRL on COR
Limit calling 
permissionsCOS (G2 and 
System 85 only)Set COS 
restrictions
COR (G1, G3, and 
System 75 only)Set FRL
Set calling party 
restrictions or 
outward restrictions
Set COR to COR 
restrictions
Require account 
code before callsForced entry of 
account codeSet account code 
length
Administer as 
required
Create 
time-dependent 
limits on access to 
route patternsAlternate FRL (G2 
and G3r only)Set lowest value 
possible
Suppress dial tone 
after ARS/WCR 
feature access 
codeSuppress dial tone Turn off ARS/WCR 
dial tone
Screen all 
AAR/ARS callsWorld Class 
Routing (G2.2 and 
G3 only)Administer all 
capabilities
Table 2-1. Security Goals: DEFINITY ECS, DEFINITY Communications 
Systems, System 75 and System 85 — Continued
Security Goal Method Security Tool Steps 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-12 Security Goals Tables 
2
1. Methods are listed in decreasing order of importance, relative to security.
2. Basic transfer with Transfer Restriction = Digits allows access to dial tone.Prevent exit from 
Voice Messaging 
SystemLimit calling 
permissionsCOR (G1, G3, and 
System 75 only)Set low FRL
Set calling party 
restrictions or 
outward restrictions
Set COR to COR 
restrictions
COS (G2 and 
System 85 only)Set calling party 
restrictions
Restrict outgoing 
toll callsToll Analysis (G1, 
G3, and System 
75 only)Identify toll areas to 
be restricted
Prevent Transfer 
to Dial Tone
1 
(for AUDIX, 
DEFINITY AUDIX, 
and Lucent 
Technologies 
I
NTUITY Voice Mail 
Systems only)Station
RestrictionsTurn off transfer 
feature
Enhanced 
Transfer (G1 Issue 
5.0, G2, G3, 
System 75 R1V3 
Issue 2.0 and later, 
and System 85 
R2V4 and later)Set Transfer
Type=
“Enhanced”
(only for Lucent 
Technologies
PBX switches)
Basic Transfer Set Transfer
Restriction=
“Subscribers”
2
Prevent exit from 
Automated 
Attendant ServiceLimit calling 
permissionsCOR (G1, G3, and 
System 75 only)Set low FRL 
Set calling party 
restrictions or 
outward restrictions
Set COR to COR 
restrictions
COS (G2 and 
System 85 only)Set COS 
restrictions
Limit exit to 
outgoing trunksFRL Set lowest 
possible value
Restrict outgoing 
toll callsToll Analysis (G1, 
G3, and System 
75 only)Identify toll areas to 
be restricted
Table 2-1. Security Goals: DEFINITY ECS, DEFINITY Communications 
Systems, System 75 and System 85 — Continued
Security Goal Method Security Tool Steps 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-13 Security Goals Tables 
2
Table 2-2. Security Goals: MERLIN II, MERLIN LEGEND, MERLIN Plus, and 
System 25 Communications Systems
Security Goal Method Security Tool Steps
Protect Remote 
Access featureLimit access Barrier codes Set max length
Authorization 
codes (MERLIN 
LEGEND 
Communications 
System R3 only)Set max length
Turn off Remote 
Access when not 
neededRemote Access 
administrationDeactivate feature
Prevent 
unauthorized 
outgoing callsLimit calling 
permissionsSwitch dial 
restrictionsSet outward/toll 
restrictions
Set allowed/ 
disallowed lists 
Limit access to 
ARS route patternsFacility Restriction 
Level (System 25 
and MERLIN 
LEGEND 
Communications 
System only)Set lowest 
possible value
Ensure the 
integrity of 
assigned call 
restrictions on loop 
start facilitiesAutomatic Call 
Restriction Reset 
(MERLIN Plus 
Communications 
System only)Activate feature
Turn off Remote 
Access when not 
neededRemote Access 
Administration 
(System 25 and 
MERLIN LEGEND 
Communications 
System only)Deactivate feature
Deactivate feature 
(MERLIN Plus 
Communications 
System R2 only)Program feature 
button
Remote Access 
Administration 
(MERLIN II 
Communications 
System only)Deactivate feature 
from administration 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-14 Security Goals Tables 
2
Protect Remote 
System 
ProgrammingRequire password 
to access system 
programmingSystem 
Programming 
password 
(MERLIN 
LEGEND 
Communications 
System and 
System 25 only)Set password
Protect Remote 
Call ForwardingSet limit for how 
long a forwarded 
call can lastAutomatic Timeout 
(MERLIN Plus 
Communications 
System R2 only)Administer a time 
limit
Turn off remote call 
forwarding when 
not neededDeactivate feature 
(MERLIN Plus 
Communications 
System R2 only)Turn off feature 
from administration
Drop outgoing line 
at end of callGround Start 
Facilities (MERLIN 
LEGEND 
Communications 
System and 
System 25 only)Install/administer 
ground start 
facilities
Prevent exit from 
Voice Messaging 
SystemLimit calling 
permissionsSwitch Dial 
Restrictions 
(System 25, 
MERLIN II, and 
MERLIN LEGEND 
Communications 
Systems only)Set outward/toll 
restrictions
Set allowed/ 
disallowed lists 
FRLs (System 25 
and MERLIN 
LEGEND 
Communications 
Systems only)Set lowest 
possible value
Restrict transfer to 
registered 
subscribers onlyTransfer 
Restrictions 
(MERLIN MAIL R3 
Voice Messaging 
System only)Choose the 
Transfer to 
Subscribers Only 
option
Table 2-2. Security Goals: MERLIN II, MERLIN LEGEND, MERLIN Plus, and 
System 25 Communications Systems — Continued
Security Goal Method Security Tool Steps 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-15 Security Goals Tables 
2
Prevent 
unauthorized use 
of facilitiesLimit access to 
ARS route patternsFRLs Set lowest 
possible value
Restrict who can 
use outcallingCOS
(MERLIN MAIL, 
MERLIN MAIL-ML, 
and MERLIN MAIL 
R3 Voice 
Messaging 
Systems only)Select a COS that 
does not permit 
outcalling
Prevent theft of 
information via 
Voice Messaging 
SystemAssign secure 
passwordsPasswords Encourage users to 
select non-trivial, 
maximum-length 
passwords
Administer 
minimum 
password lengthPasswords 
(MERLIN MAIL R3 
Voice Messaging 
System only)Administer a 
minimum 
password length of 
at least 6 digits
Set number of 
consecutive 
unsuccessful login 
attempts before 
mailbox is lockedSecurity Violation 
Notification 
(MERLIN MAIL R3 
Voice Messaging 
System only)Use the Mailbox 
Lock or Warning 
Message option, 
set to a low 
threshold
Table 2-2. Security Goals: MERLIN II, MERLIN LEGEND, MERLIN Plus, and 
System 25 Communications Systems — Continued
Security Goal Method Security Tool Steps 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Security Risks 
Page 2-16 Security Goals Tables 
2
1. The risk of toll fraud applies only if the Remote Administration Unit (RAU) is installed
with the PARTNER II or PARTNER Plus Communications System.
Table 2-3. Security Goals: PARTNER II and PARTNER Plus Communications 
Systems
Security Goal Method Security Tool Steps
Protect Remote 
Access1Do not use 
unattended modeAttended mode
(RAU)None (Attended 
mode is system 
default)
Prevent exit from 
Voice Messaging 
SystemRestrict who can 
dial outSwitch Dial 
RestrictionsUse line access 
restrictions, 
outgoing call 
restrictions, 
allowed lists, and 
disallowed lists
Prevent theft of 
information via 
Voice Messaging 
SystemAssign secure 
passwordsPasswords 
(PARTNER Plus 
Communications 
System R3.1 and 
later, and 
PARTNER II 
Communications 
System R3 and 
later)Encourage users to 
select non-trivial, 
maximum-length 
passwords
Administer 
minimum 
password lengthPasswords 
(MERLIN MAIL R3 
Voice Messaging 
System only)Administer a 
minimum 
password length of 
at least 6 digits
Restrict who can 
use outcallingCOS Select a COS that 
does not permit 
outcalling
Set number of 
consecutive 
unsuccessful login 
attempts before 
mailbox is lockedSecurity Violation 
Notification 
(MERLIN MAIL R3 
Voice Messaging 
System only)Use the Mailbox 
Lock or Warning 
Message option, 
set to a low 
threshold
Prevent 
unauthorized use 
of facilitiesRestrict who can 
dial outSwitch Dial 
RestrictionsUse line access 
restrictions, 
outgoing call 
restrictions, 
allowed lists, and 
disallowed lists; 
assign to VMS hunt 
group extensions 
						

							Large Business Communications Systems 
Page 3-1  
3
BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
3
3Large Business Communications 
Systems
This chapter provides information on protecting the following:
nDEFINITY ECS Release 5 and later
nDEFINITY Communications Systems
nSystem 75
nSystem 85
The first section of this chapter, ‘‘
Keeping Unauthorized Third Parties from 
Entering the System’’ details the major ways third parties enter the system and 
tells how to keep them from doing so. The second section, ‘‘
Tools that Restrict 
Unauthorized Outgoing Calls’’details features within the system that prevent 
unauthorized egress from the system. The third section, ‘‘
Security Measures’’ tells 
how to use the tools described in the preceding section. The final section, 
‘‘
Detecting Toll Fraud’’ details methods for monitoring the system and determining 
the effectiveness of the security measures you implemented.
Other chapters detail additional security measures to protect your equipment:
nChapter 5 contains security measures to protect the attached voice 
messaging system. For general security measures, refer to ‘‘
Protecting 
Voice Messaging Systems’’ on page 5-2. For product-specific security 
measures, refer to ‘‘
DEFINITY ECS, DEFINITY Communications Systems, 
System75, and System85’’ on page 5-4.
nChapter 6 contains security measures to protect the Automated Attendant 
feature of your communications system. See ‘‘
DEFINITY ECS, DEFINITY 
Communications Systems, System75, and System85’’ on page 6-1.
nAppendix D provides instructions for administering the features of the 
DEFINITY G3V3 and later (which includes DEFINITY ECS), specifically 
designed to provide protection from toll fraud. 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Large Business Communications Systems 
Page 3-2 Keeping Unauthorized Third Parties from Entering the System 
3
Keeping Unauthorized Third Parties
from Entering the System
How Third Parties Enter the System
The major ways in which unauthorized third parties gain entry into the system are 
as follows:
nRemote Access
nRemote Maintenance Port
nVectors
nTransfers from adjunct systems, including voice mail systems, call 
prompters, and voice response systems.
Protecting the Remote Access Feature
Remote Access, or Direct Inward System Access (DISA), allows callers to call into 
the PBX from a remote location (for example, a satellite office or while traveling) 
and use the system facilities to make calls. When properly secured, the Remote 
Access feature is both cost-efficient and convenient. However, every security 
measure has an offsetting level of inconvenience for the user. These 
inconveniences must be weighed against the possible risk of toll fraud.
Security Tips
nEvaluate the necessity for Remote Access. If this feature is not vital to your 
organization, consider deactivating the feature. If you need the feature, use 
as many of the security measures presented in this chapter as you can.
nUse a unpublished telephone number for this feature. Professional hackers 
scan telephone directories for local numbers and 800 numbers used for 
Remote Access. Keeping your Remote Access number out of the phone 
book helps prevent it from getting into the wrong hands. Avoid 
administering a night service destination to Remote Access on any 
published number.
nKeep an authorized user list and reevaluate it on a need-to-have basis.
nIf possible, administer Remote Access (DEFINITY ECS, DEFINITY G1, 
G3, and System 75) so no dial-tone prompt is supplied for entry of the 
Authorization Code. No dial tone after a Remote Access call is connected 
discourages most hackers who listen for dial tone or use modems to detect 
dial tone.
nRestrict the bands or area code sets when you offer Remote Access on an 
800 number. If all your authorized users are on the east coast, for example, 
do not provide trunks that allow calling in from San Francisco. 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Large Business Communications Systems 
Page 3-3 Keeping Unauthorized Third Parties from Entering the System 
3
nRequire maximum length barrier codes and authorization codes. For 
System 75 R1V1 and R1V2, require the entry of a barrier code. For 
System 85 and releases of DEFINITY G2.1 and G2.2 prior to 3.0, require 
either a barrier code or an authorization code. For DEFINITY G2 and 
System 85, require the entry of 11 digits (4-digit barrier code and 7-digit 
authorization code). For DEFINITY G1, G2.2 Issue 3.0 and later, DEFINITY 
G3, DEFINITY ECS, and System 75 R1V3, require the entry of 14 digits (a 
7-digit barrier code and a 7-digit authorization code) before users can gain 
access to the feature. 
nDo not assign barrier codes or authorization codes in sequential order. 
Assign random number barrier codes and authorization codes to users so if 
a hacker deciphers one code, it will not lead to the next code.
nSince most toll fraud happens after hours and on week-ends, restrict the 
hours that Remote Access is available.
Disabling/Removing Remote Access
For the “n” versions of DEFINITY G1, G2.2 Issue 3.0 and later, DEFINITY G3, 
DEFINITY ECS, System 85 R2V4n, and System 75 R1V3, as an additional step 
to ensure system security, the Remote Access feature may be “permanently” 
disabled if there is no current or anticipated need for it. Permanent removal 
protects against unauthorized remote access usage even if criminals break into 
the maintenance port. Once Remote Access is permanently disabled, however, it 
will require Lucent Technologies maintenance personnel intervention to reactivate 
the feature.
See your Account Representative for information on the North American Dialing 
Plan, and on the “n” upgrade. See Appendix C for procedures to permanently 
disable the Remote Access feature.
Tools to Protect Remote Access
You can help prevent unauthorized users from gaining access to the PBX system 
by using the following tools. (See Table 3-1.) 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Large Business Communications Systems 
Page 3-4 Keeping Unauthorized Third Parties from Entering the System 
3
*For ASAI, see the applicable product feature description.
Barrier Codes
Figure 3-1 illustrates how barrier codes and/or authorization codes can provide 
added security for Remote Access calls. Refer to this flowchart as necessary 
throughout the sections on Barrier Codes and Authorization Codes.
Table 3-1. Security Tools for Remote Access
Security Tool Switch Page #
Barrier Code All3-4
Authorization Code DEFINITY ECS, 
DEFINITY G1, G2, G3, 
System 85, and 
System 75 (R1V3)3-7
Feature Access Code 
AdministrationAll3-8
Trunk Administration All3-8
Remote Access Dial Tone  DEFINITY ECS, 
DEFINITY G1, G2, G3, 
System 85, and 
System 75 (R1V3)3-8
Night Service All3-8
Call Vectoring DEFINITY ECS and 
DEFINITY G33-9
Call Prompting/ASAI* DEFINITY ECS and 
DEFINITY G2 and G33-9
Barrier Code Aging/Access 
LimitsDEFINITY G3V3 and 
later including 
DEFINITY ECS3-61
Security Violation Notification 
(SVN)DEFINITY ECS and 
DEFINITY G33-53
Status Remote Access 
CommandDEFINITY G3V4 and 
later including 
DEFINITY ECS3-10
Logoff Screen Enhancements DEFINITY G3V4 and 
later including 
DEFINITY ECS3-10