Maintenance Description
Issue 8.0 July 2002
9-63
Figure 9-20. Dual Ring Interworking Circuit (Primary Node Failure)
When an incoming OC-48 loss-of-signal condition is detected by the secondary
node (node 3) and the termination node (node 5), the secondary node and the
termination node perform 2-fiber ring protection switching. The termination node
routes traffic on the DRI circuit around the ring through the secondary node to the
other ring. Traffic from the other ring is routed through the secondary node (node
3) to the termination node (node 5). For more information about 2-fiber ring
protection switching, refer to "2-Fiber Ring Protection Switching" in this section.
Figure 9-21 shows a dual ring interworking application with a secondary node
failure.
Primary Secondary
Low Speed
Interface
Node 4 Node 3
Other
Ring
Node
Other
Ring
Node
FT-2000
Line-Switched
Ring
Node 5
Node 1
Node 2