| 摘要 |
<p>A single, normally inactive, protection ring (22) provides protection against a working channel failure in a fiber optic ring network (10). The protection channel (22) is established and put into operation by a series of steps that are triggered by the detection of signal degradation or loss of light from one transponder by the other transponder. Each node (20A, 20B, 20C, 20D) reacts to a failure of another node in substantially the same way. Incoming traffic from external sources is rerouted from a working input-output interface to a protection interface, to establish a path for the protection signal. Signals are sent between nodes enabling the two nodes to resume communication. Only the portion of the protection ring (22) between nodes (20A, 20B, 20C, 20D) is placed into service.</p> |
