TEST METHOD FOR NETWORK ELEMENT OF OPTICAL COMMUNICATION SYSTEM AND THE NETWORK ELEMENT

PROBLEM TO BE SOLVED: To provide the test method by which optical connection between modules is discriminated even when the network element has been installed. SOLUTION: The network element(NE) of an optical communication system includes various modules (D1-D3, S1-S8, X1-X12) and at least one auxiliary module (DS, SS). Then the optical connection of them is tested by sequentially turning on/off a laser source of the modules (D1-D3, DS, S1-S8, SS) that include at least one laser source and using a detector(DET) placed in the modules (S1-S8, SS, X1-X12) and having optical inputs (P0RT1, PORT2) to measure whether or not any signal loss is produced in succeeding modules.