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Cisco ONS 15454 Reference Manual, R8.5.x
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Chapter 12 SONET Topologies and Upgrades
12.4.2 Path Protection DRI
Figure 12-22 ONS 15454 Traditional Path Protection Dual-Ring Interconnect
Figure 12-23 shows ONS 15454 nodes in an integrated DRI topology. The same drop-and-continue traffic routing occurs at two nodes, rather than four. This is achieved by installing an additional OC-N trunk at the two interconnect nodes.
Path Selector
Primary Path, Primary
Return Path, Secondary
Return Path, Primary
Primary Path, Secondary
UPSR
Ring 1
Duplicate
Signals
Pass-through
Node
UPSR
Ring 2
Bridge
85761
Node 1
Node 2Node 3
Node 5Node 4
Node 7Node 6