摘要 |
A defect notification method and apparatus for use in a multipoint ATM network so as to avoid the transmission of defect notification cells in an overlapped manner. In the invention when a connecting point detects a defect in a lower layer and when the connecting point is not a branching point the connecting point sends a first defect notification signal in the downstream direction of a first connection. When the connecting point receives the first defect notification signal and when the connecting point is a branching point, the connecting point terminates the first defect notification signal, sends a quasi-defect notification signal in the downstream direction of the first connection, and returns a second defect notification signal in the downstream direction of a second connection in the opposite direction of the first connection. Connecting points in the downstream direction of the first connection transfer the quasi-defect notification signal in the downstream direction of the first connection without processing and end points, upon receiving the quasi-defect notification signal, execute a predetermined state transition.
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