Application of Tangent RRPP Rings

Metro Ethernet typically uses two-layer rings:

• One layer is the aggregation layer between aggregation devices PE-AGGs (for example, RRPP domain 1 in Figure 1).

• The other layer is the access layer between PE-AGGs and UPEs (for example, RRPP domain 2 and RRPP domain 3 in Figure 1).

Figure 1 Tangent RRPP rings

Tangent RRPP rings can be used in this scenario, as shown in Figure 1. The aggregation layer and access layer are RRPP rings and the different layer's rings are tangent.