Westermo RedFox Series - Manual (Page 323)

Westermo OS Management Guide
Version 4.17.0-0
(see fig. 15.2a ) or the nodes in the super-ring can be shared, see fig. 15.2b .
Sub−ring Sub−ring Sub−ring
Sub−ring
a) b)
Super−ring Super−ring
RiCo RiCo
FRNT
RiCo RiCo
FRNT
RiCo RiCo
FRNT
RiCo RiCo
FRNT
FRNT FRNT
Figure 15.2: Two sub-rings connecting to (a) individual nodes in the super-ring, or
(b) shared nodes in the super-ring.
The topology can be extended even further by connecting sub-rings to sub-rings
in a tree structure with a super-ring as root.
Fig. 15.3 shows two examples, a
ladder topology (a) and a tree topology (b).
15.1.1.1 Ring Coupling and Routing
FRNT Ring Coupling is a function to connect FRNT rings at layer-2 (switching).
This improves capacity and failover performance compared to layer-3 (routing)
mechanisms such as OSPF (
chapter 27 ). Nevertheless, routing techniques have
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