Private Unified Message System by Using an Extension Number Alloted by a Private Branch Exchange

PURPOSE: A private UMS(Unified Messaging System) using the extension numbers of a PBX(Private Branch eXchange) is provided to offer UMS service to extension subscribers using the PBX. CONSTITUTION: A private UMS consists of a PBX(100), a UMS server(110), and an e-mail server(120). The PBX(100) is connected with an external trunk network(130) so that the communication between a trunk subscriber(132) and an extension subscriber of the PBX(100) or between extension subscribers of the PBX(100) can be achieved. The PBX(100) comprises a plurality of extension phones(102), a public switch module(104), a subscriber switch module(106), and a digital signal processing module(108). The UMS server(110) transfers a voice/fax message from the trunk subscriber(132) to an extension subscriber of the PBX(100) in order to offer UMS service to the extension subscriber. Also the UMS server(110) transfers a voice/fax message, which is to be transferred from the extension subscriber to the trunk subscriber(132), through the PBX(100). The UMS server(110) comprises a subscriber database(112), a media translation module(114), and a message exchange module(116).