When a converse step is used to access a VRU application that returns data for a collect digits step, the opportunity for toll fraud exists when the VRU application fails to return any data. Ensure that one of the following is true to prevent toll fraud:
If the collected digits are used to route calls internally, be certain that the COR for the VDN does not allow calls to route externally.
If you have to use collected digits to route calls externally, use a password to verify that the collected digits have been passed by the VRU application. In the following vector example the VRU application returns a three-digit password followed by the eight-digit external number. The vector routes calls without the correct password to a different vector and routes calls with the correct password to the collected digits.