Lucent Technologies BCS Products Security Handbook

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-19 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
Outgoing Voice Call Detail Record 
(AUDIX Voice Mail System Only)
An outgoing call record is also created for every outbound call that is originated by 
the AUDIX Voice Mail System via a voice port. This includes call transfers, 
outcalling, and message waiting activation and/or deactivation via access codes. 
A record is also created for call attempts for the Message Delivery feature.
The outgoing voice call detail record supplies the date the call was placed, the 
time, the AUDIX Voice Mail System port number used for the call, the duration of  Table 5-4. AUDIX Voice Mail System Session Termination 
Values
ValueReason for Session Termination
01 Caller transferred out of the AUDIX Voice Mail System
02 Caller disconnected established call
03 Caller abandoned call before the AUDIX Voice Mail System answered
04 Caller entered     
05 Caller entered     from Call Answer
06 Caller entered       from Voice Mail
07 The AUDIX Voice Mail System terminated the call due to a system 
problem
08 The AUDIX Voice Mail System terminated the call due to a caller 
problem (for example, full mailbox timeout)
09 The AUDIX Voice Mail System terminated call originated by another 
AUDIX Voice Mail System
10 Transfer from an automated attendant to another Automated 
Attendant Mailbox
11 Transfer from an automated attendant to a Call Answer Mailbox
12 Transfer from an automated attendant to a Mailbox with Guest 
Greeting
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-20 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
the call, the voice mailbox id, the number dialed, and the call type as shown in 
Table 5-5
.
Unsuccessful call transfer attempts can result in multiple records being created for 
a single session. Review these records regularly for the following signs of hacker 
activity:
nFailed login attempts
nMultiple call transfers for a single session
nNumerous outbound calls from the same voice mailbox
nCalls to strange places
nHeavy volume of Transfer Out of AUDIX Voice Mail System calls
Protecting Passwords
The AUDIX, DEFINITY AUDIX, and Lucent Technologies INTUITY Voice Mail 
Systems offers passwords and password time-out mechanisms that can help 
restrict unauthorized users.
Voice mail systems R1V4 and later allow you to specify the minimum length 
required. Use a minimum of six digits, and always specify a minimum password 
length that is greater than the extension length. For example, if the extensions are 
five digits, require six or more digits for the password. A longer password is more 
difficult for a hacker to break, and offers greater system security. Table 5-5. AUDIX Voice Mail System Outgoing Call Type 
Values
Value Outgoing Call Type
10 Transfer from Voice Mail with     or     
11 Transfer from Voice Mail via return call
12 Transfer from call answer with    ,     or 
13 Transfer from automated attendant via menu selection
14 Transfer from automated attendant via extension specification
15 Transfer from automated attendant via time out
16 Transfer from automated attendant via     
17 Transfer from Bulletin Board via    ,     or 
20 Outcalling for any message
21 Outcalling for priority message
30 Message waiting activation/deactivation
40 Message Delivery
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-21 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
For the Lucent Technologies INTUITY System, administrator passwords follow 
standard UNIX conventions, but have a 6-character minimum, one of which must 
be non-alpha. Subscriber passwords can be up to 15 digits.
For DEFINITY ECS, administrator passwords are 3 to 10 characters, alpha and 
numeric. Subscriber passwords can be up to seven digits.
Voice mail subscribers are given three attempts in one call to correctly enter their 
mailbox before they are automatically disconnected. You also can specify how 
many consecutive invalid attempts are allowed before a voice mailbox is locked.
nThe AUDIX, DEFINITY AUDIX, and Lucent Technologies INTUITY Voice 
Mail Systems provide three logins, each with individual password 
protection. For the AUDIX and DEFINITY AUDIX Voice Mail Systems, only 
one of these, “cust,” is customer-controlled. For the Lucent Technologies 
I
NTUITY Voice Mail System, “cust,” “sa,” and “vm” are customer-controlled. 
For administrative access to a voice mail system, the customer must log in 
and enter a password.
You should routinely change the “cust,” “sa,” and “vm” login passwords, 
using the maximum digits allowed (10). Lucent Technologies will routinely 
change the passwords for the two voice mail system support logins.
nChange the administration password from the default.
nUse the “Minimum Password” feature, when available, to specify a 
minimum password length of at least 6 characters. Never set the minimum 
password to 0.
nMake sure subscribers change the default password the first time they log 
into the voice mail system. To insure this, make the default password fewer 
digits than the minimum password length.
See ‘‘
Administration / Maintenance Access’’ on page 2-4 and ‘‘General Security 
Measures’’ on page 2-7 for secure password guidelines. See Appendix E for 
information on how to change passwords.
Security Features
Before implementing any security measures to protect the voice mail system, it is 
important to understand how they work. You need to be aware of the possible 
trade-offs associated with each security measure listed below.
Basic Call Transfer
With Basic Call Transfer, after a voice mail system caller enters    , the system 
performs the following steps:
1. The voice mail system verifies that the digits entered contain the same 
number of digits administered for extension lengths. If call transfer is 
restricted to subscribers (for the DEFINITY AUDIX System and the Lucent *T 
						

							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-22 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
Technologies INTUITY System only), the voice mail system also verifies 
that the digits entered match the extension number of an administered 
subscriber.
2. If Step 1 is successful, the voice mail system performs a switch-hook flash, 
putting the caller on hold.
NOTE:
If step 1 is unsuccessful, the voice mail system plays an error 
message and prompts the caller for another try.
3. The voice mail system sends the digits to the switch.
4. The voice mail system completes the transfer.
With Basic Call Transfer, a caller can dial any number, provided the number of 
digits matches the length of a valid extension. So, if an unauthorized caller dials a 
transfer code followed by the first digits of a long-distance telephone number, 
such as          , the voice mail system passes the numbers on to the 
switch. (This is an example showing a 5-digit plan.) The switch interprets the first 
digit ( ) as an access code, and the following digits as the prefix digit and area 
code. At this point, the caller enters the remaining digits of the phone number to 
complete the call.
If call transfer is restricted to subscribers (for the DEFINITY AUDIX System and 
the Lucent Technologies I
NTUITY System only), the caller cannot initiate a transfer 
to an off-premises destination unless the digits entered match an administered 
subscriber’s mailbox identifier; for example, 91809. To insure the integrity of the 
subscriber restriction, do not administer mailboxes that start with the same digit(s) 
as a valid switch Trunk Access Code. It is strongly recommended that all transfers 
be restricted to subscribers when Basic Call Transfer is used.
Enhanced Call Transfer
With Enhanced Call Transfer, the voice mail system uses a digital control link 
message to initiate the transfer and the switch verifies that the requested 
destination is a valid station in the dial plan. With Enhanced Call Transfer, when 
voice mail system callers enter     followed by digits (or     for name 
addressing) and  , the following actions take place:
1. The voice mail system verifies that the digits entered contain the same 
number of digits as administered for extension lengths. If call transfer is 
restricted to subscribers (for the DEFINITY AUDIX System and the Lucent 
Technologies I
NTUITY System only), the voice mail system also verifies 
that the digits entered match the extension number of an administered 
subscriber.
NOTE:
When callers request a name addressing transfer, the name must 
match the name of an AUDIX, DEFINITY AUDIX, or Lucent 
Technologies I
NTUITY Voice Mail System subscriber (either local or 
remote) whose extension number is in the dial plan.
91809
9
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-23 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
2. If Step 1 is successful, the voice mail system sends a transfer control link 
message containing the digits to the switch. If Step 1 is unsuccessful, the 
voice mail system plays an error message to the caller and prompts for 
another try.
3. The switch verifies that the digits entered match a valid station number in 
the dial plan.
nIf Step 3 is successful, the switch completes the transfer, 
disconnects the voice mail system voice port, and sends a 
“successful transfer” control link message to the voice mail system.
nIf Step 3 is unsuccessful, the switch leaves the voice mail system 
voice port connected to the call, sends a “fail” control link message 
to the voice mail system, and then the voice mail system plays an 
error message requesting another try.
With Enhanced Call Transfer, the reason for a transfer is included in the control 
link message that the voice mail system sends to the switch. For Call Answer 
calls, such as calls that are redirected to the voice mail system when an extension 
is busy or does not answer, when a caller enters   to Escape to Attendant, the 
voice mail system normally reports the transfer to the switch as “redirected.”
The switch uses this reason to determine how to proceed with the call. If the 
reason for the transfer is “redirected,” the call will not follow the destination’s 
coverage path or its call forwarding path. This is because the switch will not 
redirect a previously redirected call.
This restriction may not be acceptable where it is desirable to have the call follow 
the coverage path of the “transferred-to” station. Enhanced Call Transfer can be 
administered to allow this type of transfer. This capability is available in AUDIX 
Voice Mail System R1V7, the DEFINITY AUDIX System 3.0, and the Lucent 
Technologies I
NTUITY System. Contact your Lucent Technologies Sales 
Representative for additional details and availability.
Transfer Out of the System
The “Transfer Out of AUDIX” feature offers many conveniences for the AUDIX, 
DEFINITY AUDIX, or Lucent Technologies I
NTUITY Voice Mail System caller and 
subscriber. When Transfer Out of AUDIX is enabled, the voice mail system 
performs the following services:
nCallers can enter     or     from a voice mail session to call another 
extension. (Callers can also enter         for name addressing.)
nSubscribers can return calls from other subscribers.
nCallers can enter     to call another extension either before or after 
leaving a Call Answer message.
nCallers can enter     or   to Escape to Attendant either before or after 
leaving a Call Answer message.
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-24 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
nThe voice mail system transfers calls from the automated attendant via a 
menu selection, extension request, or time out.
nThe voice mail system transfers calls from the automated attendant or 
Bulletin Board sessions (some versions) when the caller enters    .
NOTE:
For the DEFINITY AUDIX System Release 2.2, transfers are permitted only 
to numbers administered in the transfer-dialplan screen. Refer to your 
DEFINITY AUDIX System Release 2.2 documentation for additional 
procedures and information.
Outcalling
Outcalling automatically notifies authorized voice mail system subscribers 
whenever a message arrives in their voice mail. When outcalling is activated, after 
a caller leaves a message for a subscriber, the voice mail system calls the number 
designated by the subscriber and delivers a recorded message notification. 
Outcalling also can be used for message notification when a subscriber’s phone 
does not have a message indicator lamp.
Outcalling permission may be administered on a per-subscriber and a per-COS 
basis in the voice mail system. The maximum number of digits to be used for 
outcalling is administered on a per-system basis.
NOTE:
This feature is not affected by Enhanced Call Transfer.
AMIS Networking
AMIS Networking (the DEFINITY AUDIX System, the AUDIX Voice Mail System 
R1V6 and later, and the Lucent Technologies I
NTUITY System) allows voice 
messages to be sent to and received from subscribers on other vendors’ voice 
messaging systems. This service is based on the Audio Message Interchange 
Specification. This feature allows calls to be placed to off-premises voice 
messaging systems.
Message Delivery
AMIS Networking (the DEFINITY AUDIX System, the AUDIX Voice Mail System 
R1V6 and later, and the Lucent Technologies I
NTUITY System) offers a message 
delivery service that delivers voice messages to any designated telephone 
number. As in the case of outcalling, this feature allows calls to be placed to 
destinations that are off-premises.
Security Measures
Where indicated, the security measures in this section apply to specific releases 
of both the AUDIX Voice Mail System and the switch.
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-25 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
Disallow Outside Calls
!CAUTION:
If TAC calls are permitted, they may be accepted as a valid extension 
number. Even with Enhanced Call Transfer activated, toll hackers may be 
able to enter a TAC to get an outside line if 3-digit station numbers and 
3-digit TACs are used.
The Enhanced Call Transfer feature is available on a voice mail system integrated 
with the System 85 R2V4, System 75 R1V3, Issue 2.0, and later software 
releases, DEFINITY Generic 1, Issue 5.0, and later software releases, DEFINITY 
Generic 2, DEFINITY Generic 3, and DEFINITY ECS. If you have an earlier 
release but want the added security offered by Enhanced Call Transfer, consider 
upgrading to the required PBX software. Use the following procedures to activate 
Enhanced Call Transfer.
NOTE:
For System 75 R1V3, Issue 2.2 is required if you are using 3-digit extension 
numbers.
For ALL systems (DEFINITY ECS, DEFINITY G1, G2, G3, System 75, and 
System 85 R2V4):
1. On the AUDIX Voice Mail System R1 system:appearance form, enter y in 
both the Call Transfer Out of AUDIX field and in the Enhanced Call 
Transfer field.
Then press  .
or
For the DEFINITY AUDIX System and the Lucent Technologies I
NTUITY 
System, use the system-parameters features form and enter enhanced in 
the Transfer Type field. Then press  .
NOTE:
When the Enhanced Call Transfer feature is activated, there is a 
change in how the Escape to Attendant feature works. If a calling 
party enters   or     to transfer to the covering extension after 
being redirected to the voice mail system, the call does not follow the 
coverage path when the covering extension is busy or does not 
answer. The AUDIX Voice Mail System R1V7, DEFINITY AUDIX 
System 3.0, and Lucent Technologies I
NTUITY Voice Mail System 
allow calls to follow a coverage path.
2. On the AUDIX Voice Mail System R1 Maintenance:audits:fp form, tab to 
the Service Dispatcher field and enter x.
Tab to the Start field and enter x.
Then press  .
Change/Run
ENTER
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-26 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
NOTE:
For the DEFINITY AUDIX System and the Lucent Technologies 
I
NTUITY System, no audit is required.
3. For DEFINITY ECS, DEFINITY G1, G3, and System 75:
On the switch, use change listed-directory-number to change the Listed 
Directory Number form, and enter a 4-digit extension number that routes 
calls to an attendant.
For DEFINITY G2 and System 85:
On the switch, use PROC204 WORD1 to assign a Listed Directory Number 
and display characters for the attendant console.
On the AUDIX Voice Mail System R1 System:appearance form, or 
System-parameters features form for the DEFINITY AUDIX System and 
the Lucent Technologies I
NTUITY System; if “0000” appears in the System 
Covering Extension field, change the entry to the new 4-digit Listed 
Directory Number.
After you activate Enhanced Call Transfer, test it by following the steps below:
1. Dial into your voice mail system.
2. Press  .
3. Enter an invalid extension number followed by  . 
The failed 
announcement should play, followed by a prompt for another extension 
number
.
4. Enter a valid extension number followed by  . 
You should notice that the 
call transfers much faster than with Basic Call Transfer.
Disable Transfer Out of the System
When the “Transfer Out of AUDIX” feature is teamed with Enhanced Call Transfer, 
the risk of toll fraud is minimized since the switch confirms that the number 
entered for the transfer is a valid PBX extension. However, if you do not need to 
transfer out, consider eliminating this feature (see ‘‘
Transfer Out of the System’’ 
on page 5-23 for details).
To do this, on the AUDIX Voice Mail System R1 System:appearance form, enter n 
in the Call Transfer Out of AUDIX field. For the DEFINITY AUDIX and Lucent 
Technologies I
NTUITY Systems, use the System-parameters features form, 
entering none in the Transfer Type field. 
NOTE:
If your automated attendant system uses transfer to an extension, you 
cannot use this security measure.
1. On the AUDIX Voice Mail System R1 Maintenance:audits:fp form, tab to 
the Service Dispatcher field and enter x.
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-27 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
2. Tab to the Start field and enter x.
3. Then press  .
NOTE:
For the DEFINITY AUDIX System and the Lucent Technologies 
I
NTUITY System, no audit is required.
Limit Outcalling
The measures you can take to minimize the security risk of outcalling depend on 
how it is used. When outcalling is used only to alert on-premises subscribers who 
do not have voice mail system message indicator lamps on their phones, you can 
assign an outward-restricted COR to the voice mail system voice ports.
For DEFINITY ECS, DEFINITY G1, G3, and System 75:
nUse change cor to display the Class of Restriction screen, and then create 
an outward restricted COR by entering outward in the Calling Party 
Restriction field. The COR should carry an FRL of 0. Outward calling party 
restrictions and calling permissions should be blocked from all trunk CORs.
nAssign the outward restricted COR to the voice mail system voice ports.
For DEFINITY G2 and System 85:
nUse PROC010 WORD3 FIELD19 to assign outward restriction to the voice 
mail system voice ports’ COS. Assign an FRL of 0 to the COR, and enter 
no for all Miscellaneous Trunk Group Restrictions.
When outcalling is used for subscribers who are off-site (often the message 
notification is forwarded to a call pager number), three options exist to minimize 
toll fraud: 1) the voice mail system voice ports can be assigned to a toll-restricted 
COR that allows calling only within a local area, 2) the outcalling numbers can be 
entered into an unrestricted calling list for either ARS or Toll Analysis, or 
3) outcalling numbers can be limited to 7 or 10 digits.
nOn the voice mail system subscriber form, turn off outcalling by entering n 
in the outcalling field.
nOn the voice mail system outcalling form, limit the number of digits that can 
be dialed for outcalling; allowing exactly the number of digits required to 
complete the call.
NOTE:
If outcalling is to a pager, additional digits may be required.
Protect AMIS Networking
To increase security for AMIS analog networking, including the Message Delivery 
service, restrict the number ranges that may be used to address messages. Be 
sure to assign all the appropriate PBX outgoing call restrictions on the voice mail 
system voice ports.
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							BCS Products
Security Handbook  
555-025-600  Issue 6
December 1997
Voice Messaging Systems 
Page 5-28 DEFINITY ECS, DEFINITY Communications Systems, System 75, and System 85 
5
Security Tips
nRequire callers to use passwords.
nHave the application verify that long distance numbers are not being 
requested, or verify that only permitted numbers are requested.
nUse appropriate switch translation restrictions.
nAdminister all appropriate switch restrictions on the voice mail system 
voice ports.
nYou may determine whether to allow transfer only to another system 
subscriber or to any extension of the correct extension length (that is, the 
number of digits for extensions administered through the switch). For 
example, your system may be configured to support the 4-digit plan, the 
5-digit plan, and so on. The most secure approach, which is the default, is 
to only allow transfers to other system subscribers. If you decide to allow 
transfers to any extension, then you should check the switch COR on the 
voice ports for proper restrictions.
nAdminister the voice mail system to use Enhanced Call Transfer if the 
switch software allows.
NOTE:
When configured to operate in Digital Port Emulation mode, the 
DEFINITY AUDIX System does not support Enhanced Call Transfer.
Protecting the AUDIX Voice Power System
The AUDIX Voice Power System provides both automated attendant and voice 
mail functionality. The automated attendant feature answers incoming calls and 
routes them to the appropriate department, person, or mailbox. The voice mail 
feature provides call coverage to voice mailboxes along with a variety of voice 
messaging features.
Unauthorized persons concentrate their activities in two areas with the AUDIX 
Voice Power System:
nThey try to transfer out of the AUDIX Voice Power System to gain access to 
an outgoing trunk and make long distance calls.
nThey try to locate unused or unprotected mailboxes and use them as 
dropoff points for their own messages.
Traffic Reports
The AUDIX Voice Power System tracks traffic data over various timespans. 
Reviewing these reports on a regular basis helps to establish traffic trends. If 
increased activity or unusual usage patterns occur, such as heavy call volume on 
ports assigned to outcalling, they can be investigated immediately.