Typical Topology for Subring Mode

• Typical topology for the single ring

EIPS Domain1 includes one EIPS Ring1, Master, Transit1, Transit2, and Transit3, as shown in Figure 3-1.

Figure 3-1 Topology for the single ring

This topology is characterized with fast response and short convergence time for topology changes.

• Typical topology for the intersecting ring

EIPS Domain1 includes two rings, Ring1 as the main ring and Ring2 as the sub ring. Ring1 consists of Master, Transit1, and Transit2; Ring2 consists of Edge control (Transit3), Edge assistant (Transit4), Sub Transit1, and Sub Transit2. Both Edge control and Edge assistant are transmission nodes of Ring1, as shown in Figure 3-2.

Figure 3-2 Topology for the intersecting ring

This topology is mainly applied to the scenario that a sub ring is dual homing to the uplink through two edge nodes, providing uplink backup.