Resolution
Call blocking (toll bar) can be configured to prevent unauthorized use of phones by matching a pattern of specified digits during a specified time of day and day of week, or by a specified date. Up to 32 patterns of digits can be specified. Call blocking is supported on IP phones, but not on analog Foreign Exchange Station (FXS) phones.
When a user attempts to place a call to digits that match a pattern specified for call blocking during a time period that has been defined for call blocking, a fast-busy signal is played for approximately 10 seconds. The call is then terminated, and the line is placed back in on-hook status.
Call blocking applies to all IP phones in a Cisco CallManager system, although individual IP phones can be exempted from all call blocking.
For more information, refer to these documents:
