Abstract: A voice communication apparatus that includes gateway modules in a distributed structure to drive a protocol selected by a corresponding terminal in communication with a public telephone network, so as to convert a packet and renew a state variation of a terminal allocated to itself within a group while performing the packet conversion, and a packet switching module to switch to a corresponding port while communicating between a public telephone network and the gateway module or between a LAN and the gateway module. Each module thus co-owns the information by transferring the call signal and voice by the ethernet interface on a network standard, and accordingly, the switching between the PSTN (public switched telephone network) gateway modules is simply performed. This facilitates long-distance communication with an employee, for example, who may telecommute from a remote place, thereby reducing the expense of long-distance communication.

Abstract: An internet phone-based private exchange and a call signal exchanging method thereof employing a network protocol unit, a call signal detecting/determining unit, a call converting unit which matches a protocol of the call signal from the call transmitting terminal with a protocol of a call signal supporting a receiving terminal which is to be connected by the call transmitting terminal when the protocol of the call signal of the call transmitting terminal and that of the receiving terminal are different, and a task managing unit which inputs the call signals of the call transmitting terminals from the gate keepers and transmits IP addresses of the receiving terminals which are to be connected by the call transmitting terminals to the terminal gate keepers.

Abstract: An Internet phone protocol including a physical hierarchy for providing a mechanic and functional units for connecting, maintaining and releasing between linking media; a device driver hierarchy for defining driving characteristics of each electric and mechanic unit of the physical hierarchy; a real time operating system (RTOS) programming hierarchy for controlling an overall system; a user datagram protocol (UDP)/Internet protocol (IP) hierarchy for defining characteristics for processing a packet stream in packet change; an interface hierarchy for receiving a user's intention to a system; a voice/real-time transport protocol (VOICE/RTP) hierarchy for linking a voice channel between Internet phones; and an independent multimedia office communication system protocol (referred to as MOCS protocol hereinafter) hierarchy for rendering Internet phones to store in exchange status information to each other for independent and direct linking, by which one Internet phone indenpendently and directly transfers its