| 摘要 |
<p>PURPOSE: To unnecessitate a dedicated circuit for mutually connecting private branch exchanges(PBX). CONSTITUTION: An intelligent network is used together with an information communication network system and provided with a virtual private network(VPN). The VPN has plural PBX respectively connected with a public telephone network and the intelligent network inside a system. When the call of a certain VPN is started by a subscriber connected to the PBX, a message is transmitted through the connected intelligent network to the PBX at the destination, and the connected PBX and a local exchange are connected. Next, the message is transmitted from the local exchange through the intelligent network to the service access point of VPN and the service access point connects the local exchange for subscriber and the PBX at the destination through the public telephone network.</p> |
