Patent ID: 8804491

Claim:
A recovery method for a ring-based network, and the ring-based network comprising a plurality of nodes, and each of the nodes having a priority value of each of the adjacent nodes and their own priority value, and the nodes including a first node, a second node and a third node, and the first node being between the second node and the third node, and the recovery method comprising the steps of: transmitting a link-down packet having a priority value of the second node and the first node from the second node to the ring-based network and transmitting a link-down packet having the priority value of the third node and the first node from the third node to the ring-based network; forming a forward link by a backup link of the ring-based network; examining the priority values of the link-down packets by each of the nodes at both ends of the backup link except downed node after receiving the link-down packets; and determining which one of the plurality of nodes is downed if each of the link-down packets has the priority value of the downed node simultaneously; wherein each of the nodes at both ends of the backup link discards a latter received link-down packet without transmitting to the rest of nodes; transmitting a link-up packet from the first node, the second node and the third node separately after the first node is repaired, wherein each of the link-up packets has two priority values of nodes selected from the group consisting of the first node, the second node and the third node; comparing the priority values of the first node, the second node and the third node with each of the link-up packet after the first node is repaired, such that a ring port of the first node, the second node or the third node enters into a forward status or a blocked status after the first node is repaired; forming a blocked link or the forward link between two of the ring ports selected from the group consisting of the first node, the second node and the third node; clearing the priority value of the first node by the second node after the second node transmits the link-down packet with the priority values of the second node and the first node; and clearing the priority value of the first node by the third node after the third node transmits the link-down packet with the priority values of the third node and the first node.