| 摘要 |
PURPOSE:To continue the transmission in plural groups at a fault by checking with a path comprising one optical transmission line, an adjacent node and other optical transmission line to the adjacent node in detecting a fault so as to inhibit the transmission or reception of data in response to the faulty state. CONSTITUTION:When one of bidirectional transmission lines (including inside of a node) is faulty, other transmission line is used effectively. When both bidirectional transmission lines are faulty at the same location, the connection of a ring is opened to form linear form to transmit the data. When both transmission lines are faulty at different locations, plural separated lines are constituted to transmit data between nodes capable of transmission. In the case of the restoration of a faulty node, in the case of bringing the faulty node into the operating state or restoring the opened optical line into the ring connection, a reset packet is provided to inform it to all nodes. |
