LOWER MAIN DEVICE AND NON-IP TERMINAL HOUSING METHOD

摘要

The objective of the present invention is to provide a lower main device capable of connecting a non-IP terminal such as a digital terminal to an upper main device using an IP network and of accommodating call control. The lower main device behaves as one or more IP terminals toward the upper main device and houses one or more non-IP terminals which each correspond to the one or more IP terminals.