Patent ID: 7333472

Claim:
An Internet protocol telephony exchange system connected to an IP (Internet Protocol) network and a PSTN (Public Switched Telephone Network), for performing call control services of legacy terminals and IP terminals by controlling an Internet Protocol and an exchange call control procedure, comprising: at least one IP terminal connected to the IP network, for containing a user interface which generates user information or converts received user interface information into information of a user-identifiable state, and performing a VoIP (Voice over Internet Protocol) function in compliance with a predetermined data communication protocol procedure; an IP driver connected to the IP network, for controlling an IP end point at which the IP terminals are positioned, upon receiving IP terminal connection information and call control information based on the data communication protocol procedure; and an IP-PBX (Internet Protocol-Private Branch Exchange) including: a database having subscriber information including phone numbers of a plurality of legacy terminals and the IP terminals, port numbers, and IP address information; an exchange interface connected to the IP network, for receiving the user information from the IP terminals, and transmitting call control information to the IP driver and the IP terminals over the IP network; a gateway card connected to the IP network, for establishing a traffic channel between the IP terminals and the legacy terminals upon receiving IP terminal connection information based on the data communication protocol procedure and call control information; and a call control module for searching the database on the basis of call origination information transmitted from the IP terminals and the legacy terminals, analyzing a termination-side number, and establishing a call connection service with the legacy terminals or the IP terminals via the exchange interface, the gateway card, and the IP driver, such that when the IP terminals generate user information, the call control module provides the IP terminals with a variety of tone and user interface information for controlling the IP terminals by analyzing phone numbers and port numbers of the IP terminals in such a way that the IP terminals generate call signals in the same number system as the legacy terminals.