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.