Abstract: A terminal for interconnecting a large number of subscriber telephone circuits with a large bandwidth fiber optic transmission system. A system backplane includes a large number of connectors that each can receive a subscriber printed circuit card which is connectable to subscriber telephone equipment. Each connector is connected to several separate communication buses that each carry a number of communication channels from the fiber optic system, but a primary bus position of each connector is connected to a single, unique bus. This allows each card to have a dedicated bus for up to the number of communication channels of the bus, with additional channel capacity available from primary buses of other connectors, if necessary.