| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a communication system, packet exchange, and terminal device capable of setting area groups for every extension terminal thereby controlling origination and termination. SOLUTION: Packet exchanges 2 and 3 set the closed area groups by the extension terminals. When an extension terminal 4 adds closed area facility to a packet to an extension terminal 7 belonging to the same closed area group and sends the packet, the packet exchange 2 deletes the closed area facility, refers to a closed area group table, and supplies the packet given a closed area group index number to the packet exchange 3 through a public packet network 1. The packet exchange 3 performs termination control according to the closed area group index number in the received packet, and deletes the closed area group index number in the received packet and adds closed area facility when the packet is a packet to an extension terminal in the previously set closed area group, thereby supplying it to the extension terminal 7.</p> |
