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, User2, and User3 communicate with each other through one OTU2 service separately. On station A, the TOM board accesses eight Any services and then converts them into four ODU0 or two ODU1 services. The four ODU0 or two ODU1 services are then sent to two NS2 boards according to the actual service requirement. Each NS2 board converges the received ODU0 or ODU1 services and other accessed services into one OTU2 service.

In this example, a TOM board and two NS2 boards should be configured on station A, a TOM board and an NS2 board should be configured on station B and station C.