About this task
Use this procedure to make a Bridge Line Appearance (BLA) audio call.
A typical use case for the BLA feature is a boss and secretary scenario. In this scenario, the primary number is of the boss, and call appearances of the primary number are configured on the extension of the secretary. When someone calls the boss, the boss or the secretary can answer the call. If the call is answered first by the secretary, the boss can bridge onto the call.