Mitel Corporation

John R Whitbread

Graham A Neathway

Robert A Durance

John A Cribb

A call denial apparatus for identifying a telephone subscriber's line out of a group, whereby access to a trunk is denied in the event the subscriber dials one or a group of predetermined digits. A subscriber not to be denied access to the trunk is identified by applying a tracer signal to the seized trunk and the tracer signal on one of the group of subscribers' lines is detected. Accordingly specially modified telephone sets and lines are not required.

Growing community of inventors

Ashton, Canada

John R Whitbread