Technical information

Voice Messaging Systems
6-2 Issue 7 June 2001
Protecting Voice Messaging Systems
Voice messaging toll fraud has risen dramatically in recent years. Now more than
ever, it is imperative that you take steps to secure your communications systems.
Callers into the voice messaging/auto attendant system may transfer to an
outgoing trunk if adequate security measures are not implemented (see Figure
6-1).
In addition, mailboxes associated with voice messaging systems can facilitate toll
fraud or industrial espionage if they are accessible to unauthorized users.
Figure 6-1. Call Transfer Through the PBX
Criminals attempt to transfer to the following codes:
 ARS Dial Access Codes (most likely the digit “9”)
 Trunk Access Codes (TACs)
 Trunk Verification Codes, Facility Test Call Access Codes, or Data
Origination Codes
CO
DID
800
SDN
Voice
Messaging
Auto
Attendant
PBX