PURPOSE: To attain communication between subscriber's terminal equipments by providing a connection controlling between an ISDN digital line connector and plural terminal equipments and setting a subscriber's exclusive packet.

CONSTITUTION: A connection controller 1 is provided between an ISDN digital line connection 4 and plural terminal equipments 2a-2c connected mutually by a 2-wire two pair wiring, and a subscriber's exclusive packet is provided to a control packet sent from the terminal equipment 2a-2c. Thus, the connection controller 1 recognizes the subscriber's exclusive packet and the connection/ disconnection of terminal equipment is applied according to the constant, then the communication between terminals in the same subscriber is attained.