Abstract: A method of providing a Private Telephone Network over a Public Telephone Network is described. A Private Network is a telecommunications service which has controlled access, and is generally provided to customers having two or more geographic locations. A Private Network is provided by embedding originating customer site identification and a Private Network Routing Code into an Initial Address Message at the originating End Office associated with the originating customer site. This Initial Address Message is routed to a Service Switching Point by the Private Network Routing Code. At the Service Switching Point, reference is made to databases defining the members of the Private Network, and a destination End Office identification and a destination customer site identification associated with the destination customer site is embedded into the Initial Address Message.