H3C S5120-EI Series Operation Manual page 261

Single ring
Figure 1-2 Single ring
There is only a single ring in the network topology. In this case, you only need to define an RRPP
domain.
Tangent rings
Figure 1-3 Tangent rings
There are two or more rings in the network topology and only one common node between rings. In this
case, you need to define an RRPP domain for each ring.
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