Signal conversion for fault isolation

To readily isolate a fault in a network adaptable for distributed restoration of disrupted traffic, each node of the network is provisioned with the functionality of being able to detect an incoming alarm signal and convert such alarm signal into a non-alarm signal with an embedded message for further propagation to nodes downstream thereof. Thus, the custodial nodes that first detected the alarm resulting from the malfunction would convert the alarm signal into a non-alarm signal and propagate the non-alarm signal to their respective downstream nodes. By thus changing the alarm signal into a non-alarm signal by the nodes that first detect the alarm, the management of the network ensures that the alarm is detected by only two adjacent nodes, thereby making the fault isolation quick and simple. In order not to disturb the functioning of the nodes outside the distributed restoration network, when the converted non-alarm signal reaches an access/egress node of the distributed restoration network, it is reconverted back into an alarm signal to be propagated to nodes outside of the network.