This section describes how to configure the service for a ring network.
Refer to Figure 1, the optical NEs (ONEs) A, B, C and D form a ring network, and all the ONEs function as OADM stations.
User1 and User2 communicate with each other. Four bidirectional OTU1 services are available between station A and station B. On station A, the TOM board accesses four OTU1 services and then converts them into four OTU1 services through Any re-encapsulation.

In this example, a TOM board should be configured on station A and station B.