АМАТЕК AN-SGM28P24-400 [145/322] Erps working principle

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10.3 ERPS Working principle

10.3.1 Normal state

(1)

All nodes are connected in a ring by physical topology；

(2)

Loop protection protocols ensure that loops are not blocked by blocking the RPL link. As

shown in the figure above, the link between Node1 and Node4 is RPL link；

(3) Fault detection is performed for each link between adjacent nodes。

10.3.2 Link failures

(1)

The nodes adjacent to the fault and fault link link congestion, and the use of RAPS (SF)

message to the other nodes report the fault on the ring, as shown above, assuming Node2, Node3

between Node2 and Node3 link failure, waiting for the holdoff timer after a timeout, it will block

the link fault, respectively to ring network nodes send the RAPS message (SF)；

(2)

RAPS (SF) message trigger RPL has the node to open the RPL port. The RAPS (SF)

message also triggers all nodes to update their respective MAC table entries, and then the nodes