a terminal equipment is connected in a first optical network and connected , via a conductive path , to a predetermined one of a plurality of communication devices connected in a second optical network . the above terminal equipment includes an optical transmitter / receiver unit , a controller for controlling the above predetermined one of the communication devices in order to monitor the communication devices connected in the second optical network , and a selector unit . this selector unit transfers , via a control path coupled to the predetermined one of the communication devices , a poling signal from the first optical network to a specified one of the communication devices addressed by the poling signal , and sends back , to the first optical network , control data which shows a status of the specified one of the communication devices connected in the second optical network and which is received , via the control path , from the specified one of the communication devices .