| 摘要 |
<p>PURPOSE: A method for offering IP PTT service through a group call is provided to use IP PPT service in both wired/wireless public IP network environment and wired/wireless internal IP network environment. CONSTITUTION: When a call signal is received from a first terminal, an IP(Internet Protocol) PTT(Push-To-Talk) proxy server calls the second terminal that is requested by the first terminal(S230). The IP PTT proxy server assigns a first RTP(Real-time Transport Protocol) port to the first and the second terminal and transmits, and the second RTP port is received from the first and the second terminal. When the request to talk signal is received from the first or the second terminal, the IP PTT proxy server opens the first RTP port of the terminal receiving the request to talk signal(S236). The second RTP port of the terminal dispatching the request to talk signal is opened. The voice message is transmitted from the terminal in which the request to talk signal is received with the terminal in which the request to talk signal is not received.</p> |
