Example of a Router Receiving Only an RDI-P Alarm

In Figure 17, the X indicates that the LOS or LOF occurs in the section between ADM1 and ADM2.

All diagnostics are from the perspective of Router2 (the Juniper Networks router).

Figure 17: Example of a Router Receiving Only an RDI-P Alarm

What It Means

In Figure 17, the progression of events occurring after the failure is as follows:

1. ADM1 detects an LOS or LOF on an incoming SONET section.
2. ADM1 sends an RDI-L to ADM2.
3. ADM1 sends an AIS-P downstream to Router1.
4. Router1 sends an RDI-P upstream to Router2.
5. Router2 only receives an RDI-P alarm.