| 摘要 |
PURPOSE:To attain the coexistence of the systems and to improve the utilizing efficiency by providing a system employing an ISDN in parallel with a network system comprising a private line and plural equipments and providing a means to select a system in the operating state to the network system. CONSTITUTION:A network system employing an integrated services digital network ISDN 7 is provided in parallel with a network system comprising a private line 10 and plural equipments 6. Then a changeover module 110 of a 2nd PISTA 5 selecting one system in the operating state is provided. Since an interface module 101 utilizing the ISDN 7 in interfaces selected by a changeover means of the module 110 has a means selecting an opposite equipment to be connected, a specific equipment is selected. Thus, the network is provided in a form of coexistence with an existing network and the utilizing efficiency is improved. |
