PLANET MGSW-28240F - Manual (Page 367)

User’s Manual of MGSW-28240F
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 the Ring Protection Link or RPL . Each switch will send ETH-CCM
message to check the 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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