Method for confirming the opposite party and communication system using the same

The present invention relates to a communication system using before you start or join a call session, check the other side (sender or recipient) and pre-party check to determine whether the start of the call or session and how to join them. If they check process according to the invention, the transmitter word transfer receiving terminal via a server, the media information about the call or session, the receiver checks a media information that is output to the receiving terminal determines the call or session connection . The receiving terminal may send a message with the reason for denial refused to deny participation in the call or session. In addition, the server may be output by transmitting the pre-stored media information to each terminal. Communication system, the media information, SIP, RTP / RTCP, a session connection