| 摘要 |
PROBLEM TO BE SOLVED: To achieve an optical line changeover of optical lines of a redundant structure regardless of apparatus operations.SOLUTION: The transponder includes: a protective timer 222 that is activated when an alarm display signal transmitted from a client apparatus 100 (106) is received; and a control part 224 that controls a state of optical transmission to an optical coupler 101b (105b) when the protective timer 222 timeouts. A timeout value of the protective timer 222 is set at a different value from a timeout value of a protective timer at another transponder. |
