Ring - Interlogix NS4702-24P-4S-4X User Manual

4.19 Ring

ITU-T G.8032 Ethernet Ring protection switching (ERPS) is a link layer protocol applied on Ethernet loop protection
to provide sub-50ms protection and recovery switching for Ethernet traffic in a ring topology.
ERPS provides a faster redundant recovery than Spanning Tree topology. The action is similar to STP or RSTP, but the
algorithms between them are not the same. In the Ring topology, every switch should be enabled with Ring function
and two ports should be assigned as the member ports in the ERPS. Only one switch in the Ring group would be set as
the RPL owner switch in which one port, called owner port, would be blocked, and PRL neighbour switch has one port
in which one port, called neighbour port, would be blocked. The neighbour port is connected to the owner port
directly and this link is called . Each switch will send ETH-CCM message to check the
the Ring Protection Link or RPL
link status in the ring group. When the failure of network connection occurs, the nodes block the failed link and report
the signal failure message. The RPL owner switch will automatically unblock the PRL to recover from the failure.
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