Abstract: The present invention relates to a protection switching method in a communication network, the communication network including plurality of communication devices forming a linear chain and at least one non-ERPS on the nodes ERPS (Ethernet Ring Protection Switching) device connecting terminal ports of the linear chain and thereby forming a ring. In one embodiment this is accomplished by instantiating ERPS on each communication device that forms a linear chain and on each non-terminal ports of the linear chain, identifying a node or link fault in the network, wherein the link or node fault is detected by Continuity Check Message (CCM), Loss of Light (LOL), Loss of Signal (LOS), Loss of periodic continuity check messages (IEEE 802.