| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication system and an optical transmission device which can achieve improvement in failure resistance.SOLUTION: In a normal operation, for example, line cards LCm 1, LCm 2 set a transmission port TXu of user ports UPm 1, UPm 2 to be in an open state, and the line cards LCs 1, LCs 2 set the TXu of user ports UPs 1, UPs 2 to be in a cut-off state. When a failure is generated to a communication line LNa 1, for example, the LCm 2 detects the failure through a transmission port HPm 2, and then changes the TXu of the UPm 2 from the open state to the cut-off state to notify failure detection to the LCs 2 through a backplane. The LCs 2, in response to the notification of the failure detection, changes the TXu of the UPs 2 from the cut-off state to the open state. |
