Abstract: A WAN is formed using Frame Relay Protocol and a telephone network interface unit. An originating LAN sends a message to a router which communicates with a telephone network interface unit using Frame Relay Protocol. The telephone network interface unit determines the destination of a packet received from the router by interpreting the Frame Relay Protocol, and it associates a phone number with that destination. The interface unit uses the phone number to establish at least one DSO connection over a digital telephone network to a destination network interface. A destination network interface unit receives the packet from the digital telephone network and provides the packet to a router which interfaces to the destination LAN. The network interface units add or drop additional DSO channels as required by the traffic load and thereby provide variable bandwidth.

Abstract: A secure method of accessing a computer facility is provided within the data communications equipment (DCE), e.g., a modem or a terminal server, by the use of Calling Party Directory Number (CPDN). In particular, a telephone line from the local public switched telephone network is configured to provide CPDN information. This telephone line terminates in the DCE, which stores a plurality of lists, each list comprising a plurality of CPDN numbers. Upon receiving a telephone call from a calling party, the DCE takes one of three courses of action depending on the calling party's CPDN: 1) the DCE can answer the telephone call if the calling party's CPDN is on the "caller pays" list; 2) the DCE can refuse to answer the telephone call and then return the telephone call if the CPDN is on the "we pay" list; or 3) the DCE can simply not answer, or return, the telephone call if the calling party's CPDN is not found on any of the plurality of lists.