Abstract: An integrated services digital network (ISDN) private exchange device is provided, which includes connectors for connection to an ISDN local exchange, a plurality of ports for connection to respective analog telephone devices, a plurality of ports for connection to respective digital devices, and an ISDN digital port for connection to at least one additional ISDN terminal device. The private exchange device may include a pair of ports for connection to two different analog telephone devices, each having simultaneous access capability with the ISDN network. Further, the private exchange device may include four ports for connection up to four digital devices, which are each capable of simultaneously accessing the ISDN local exchange. The ISDN digital port can be connected with up to eight ISDN terminals or terminal adapters.