Abstract: A terminal multiplexer structure comprising a plurality of line interface cards and a plurality of trunk interface cards wherein each of the line interface cards is connected to at least two of the trunk interface cards and comprises a switch for switching the connection transmission from the line interface board between the two trunk interface cards.

Abstract: An optical network element comprising a plurality of subscriber line connections, a WDM unit having a plurality of WDM channel connections, a plurality of subscriber line interface cards and a plurality of trunk line interface cards for optical interfacing between the subscriber line connections and the WDM channel connections, and a switch arranged, in use, in a manner such as to be capable of switching transmission directions between the WDM channel connections and individual ones of the subscriber line connections by suitable switching of an optical path configuration between transmitter ports and receiver ports of the subscriber line interface cards and the WDM channel connections.