Private branch exchange, private branch exchange system, and terminal unit registration method

摘要

A communication address request notification which inquires about an IP address of a private branch exchange 2 is transmitted from an IP telephone 3 a to be newly accommodated. A private branch exchange 2 or an IP telephone 3 b which has received the communication address request notification transmits the IP address of the private branch exchange 2 as a communication address response notification, if the IP address of the private branch exchange 2 to be the registration destination is stored in a memory of the private branch exchange 2 or a memory of the IP telephone 3 b. Then, the IP telephone 3 a which has received the communication address response notification stores this IP address as the IP address of the private branch exchange 2 of the registration destination in the memory.