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Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter5 SONET Topologies
Path-Protected Mesh Networks
Figure5-39 A path-protected mesh network
PPMN also allows spans of different SONET line rates to be mixed together in virtual rings. Figure 5-40 shows Nodes 1, 2, 3, and 4 in a standard OC-48 ring. Nodes 5, 6, 7, and 8 link to the backbone ring through OC-12 fiber. The virtual ring formed by Nodes 5, 6, 7, and 8 uses both OC-48 and OC-12.
= Primary path
= Secondary path

Working traffic

Protect traffic
Source
Node
Destination
Node
32136
Node 1
Node 11
Node 2
Node 4
Node 5
Node 6
Node 7
Node 8Node 10
Node 9
Node 3