The concept of ring redundancy allows the construction of high-availability,
ring-shaped network structures.
With the help of the RM (Ring Manager) function, the two ends of a backbone
in a line structure can be closed to a redundant ring. The ring manager keeps
the redundant line open as long as the line structure is intact. If a segment
becomes inoperable, the ring manager immediately closes the redundant
line, and line structure is intact again.
Figure 1: Line structure
Figure 2: Redundant ring structure
RM = Ring Manager
—— main line
– – – redundant line
If a section is down, the ring structure of a
HIPER-(HIGH PERFORMANCE REDUNDANCY) Ring with up to 50
devices typically transforms back to a line structure within 80 ms (possible settings: standard/accelerated).
MRP (Media Redundancy Protocol) Ring (IEC 62439) of up to 50 devices
typically transforms back to a line structure within 80 ms (adjustable to max. 200 ms/500 ms
Example of a MRP-Ring
A network contains a backbone in a line structure with 3 devices. To increase
the availability of the backbone, you decide to convert the line structure to a
redundant ring. In contrast to the previous example, devices from different
manufacturers are used which do not all support the HIPER-Ring protocol.
However, all devices support MRP as the ring redundancy protocol, so you
decide to deploy MRP. You use ports 1.1 and 1.2 of the devices to connect
the lines.
Figure 3: Example of MRP-Ring
RM = Ring Manager
—— main line
– – – redundant line
Note: Configure all the devices of the MRP-Ring individually. Before you
connect the redundant line, you must have completed the configuration of all
the devices of the MRP-Ring. You thus avoid loops during the configuration
phase.