Patent ID: 7058171

Claim:
An IP telephone apparatus for executing a telephone call through a computer network, comprising: a main unit having a handset; a telephone line connection unit that connects to a telephone network; an external telephone connection unit being connectable to an external telephone having a handset; a dialing start command detection unit configured to detect an IP telephone dialing start command; an audio signal input/output unit that inputs/outputs an audio signal for conversation when the dialing start command unit detects the IP telephone dialing start command; a handset validation unit configured to selectively validate one of the handset of the main unit and the handset of the external telephone; an audio signal path switching unit that switches a connection target of the handset validated by the handset validation unit from the telephone line connection unit to the audio signal input/output unit when the dialing start command detection unit detects the IP telephone dialing start command; a network communication control unit, further comprising a network terminal that connects to the computer network, the network communications control unit configured to enable the audio signal input/output unit to transmit and receive the audio signal to and from the network terminal when the dialing start command detection unit detects the IP telephone dialing start command; a message transmission unit that sends to the external telephone a guidance message to selectively use one of a general telephone function for telecommunicating by use of the telephone network and an IP telephone function for telecommunicating by use of the computer network, upon reception of an off-hook signal from the external telephone; and a mode setting unit that sets one of a switch mode and a fixed mode, the switch mode for allowing a user to selectively switch between the general telephone function and the IP telephone function, the fixed mode for allowing the user to use either of the general telephone function and the IP telephone function exclusively.