This section describes how to configure 52TOM board for a ring network.
See 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. One bidirectional OTU2 service is available between station A and station B. On station A, the 52TOM board accesses four OTU1 services, decapsulates them into four ODU1 electrical signals, and then converts them into four OTU1 services. In this way, the electrical regeneration is complete.

In this example, a 52TOM board should be configured on station A and station B.