Patent ID: 6707897
Filing Date: 2004-03-16
Classification: H04M,H04Q

Abstract:
A private branch exchange comprising:at least one extension circuit to which an extension terminal is connected via an extension line; at least one trunk circuit connected to an office line; memory means for storing information on a relationship between an extension number relating to the extension circuit and information relating to a reception call number, in association with the trunk circuit, the information relating to the reception call number enabling a callback to the extension terminal; and sending means for sending the information relating to the reception call number as a caller number to the office line, when a call is transmitted from the extension terminal to the office line via the trunk circuit, wherein in a case where a transmission call request is issued from the extension terminal to the office line, with one of the trunk circuit selected, if the memory means does not store information relating to a reception call number corresponding to an extension number of the extension terminal relating to the call, the sending means sends information on caller number presentation restriction to the office line.