To help prevent toll fraud, configure your dial plan with the appropriate calling search spaces and
partitions in Cisco CallManager. These constructs enable you to specify which dialed patterns can be
reached by specific calling devices. An IP phone, for example, could have a calling search space that includes a partition with a 9.xxxxxxx pattern in it. If this is the only pattern and the only partition
associated with the calling search space on that phone, then only this pattern of digits can be dialed by
that phone.
The basic measures for preventing toll fraud include:
• Using a dial plan to reduce or eliminate toll fraud
• Blocking the transfer of calls to extension 9xxx
• Disabling IP phone auto-registration
• Restricting the calling search spaces of call forward all, voice mail, and Personal Assistant
• Blocking area codes commonly used for toll fraud
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