| 摘要 |
A transmission is disclosed for recovering from faults in transmission equipment or facilities forming so-called virtual circuits for transmitting packets in a network. Faults are detected in transmission paths associated with a network node and an individual fault indication message is generated for each network facility that has at least one virtual circuit affected by the fault. Each fault indication message includes the identity of each virtual circuit on the associated network facility affected by the fault. The message is transmitted inband on at least one of the affected virtual circuits on the associated network facility. If affected virtual circuits are terminated in the node, they are switched to alternate virtual circuits. Otherwise, the fault indication messages are transmitted over the identified facilities to other unknown nodes. A node receiving a fault indication message determines which virtual circuits identified in the message are terminated in the node and which virtual circuits pass through the node. The virtual circuits that are terminated in the node are switched to alternate virtual circuits. For virtual circuits passing through the node, the network facilities associated with them are identified and a new fault indication message is generated for each of the identified facilities. Each of the generated fault indication messages is transmitted in-band on at least one virtual circuit on the, respective, identified network facility. (FIG. 2)
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