Patent ID: 7508754

Claim:
A method operable within a system of the type in which an enterprise network provides connectivity between a plurality of enterprise telephone stations, wherein a landline connection extends between the enterprise network and a packet-switched network, and wherein a call server sits on the packet-switched network and engages in packet-based signaling with the enterprise network to set up calls inside the enterprise network between the enterprise telephone stations, the method comprising: detecting failure of the landline connection; and in response to detecting failure of the landline connection, (a) invoking a wireless wide area network (WWAN) connection between the enterprise network and the packet-switched network to allow continued passage of the packet-based signaling between the enterprise network and the call server to set up calls having bearer paths within the enterprise network between the enterprise telephone stations, and (b) at the call server, allowing setup of calls having bearer paths within the enterprise network between the enterprise telephone stations, while preventing setup of all but certain designated calls having bearer paths extending from the enterprise network and through the WWAN connection.