MAIN DISTRIBUTION BOARD SYSTEM

PURPOSE:To improve the instantaneity to serivce the request of subscriber by providing a switch group connecting output and input terminals by one to one and a switch group connecting selectively optional terminals between the subscriber accommodating terminal of an exchange and a subscriber line. CONSTITUTION:A subscriber line on service is connected to the H terminals a0- an of a jumper terminal board JF and a line not in use is connected to H terminals b0-bm. Further, the incoming terminals of a basic switch group BSW are connected to the terminals a00-ann of the jumper terminal board JF and the incoming terminals of a selecting switch matrix group SSW are connected to V terminals b00-bmm. The outgoing terminals of the basic switch group BSW and the selection switch matrix group SSW are connected to an exchange NW. Each switch group is controlled from a switch controller SC so as to stop the service to the subscribers and to start the service to new subscribers.