To improve the using convenience for a user and to set up a large campus network by connecting a public exchange telephone network PSTN and an asynchronous LAN and converting telephone traffic connected to the LAN to asynchronous data, so as to transmit through the LAN.
The public telephone network PSTN 16 or a wide area network is connected to a client personal computer PC 18 installed with a telephone equipment 11, through an asynchronous transfer mode ATM network switch 14 to constitute a private branch area network of a distributed private branch exchanging equipment PBX 10. At the time of speaking with a desired telephone equipment, messages are exchanged between the PBX within a server 12 by the control of the client PC 18 to be connected and the desired telephone set to establish a bi-directional stream through the LAN. When an external line is called, communication is executed similarly by connecting with a desired telephone set through the LAN, the PBX within the server 12 and a telephone interface.
WEIR ALAN T
VYSKOCIL RANDALL
NIESMAN DAVID F
KERGOZOU M A
