Cisco 15454-DS1-14= - 1.544Mbps Expansion Module Reference Manual page 440

12.8 Path-Protected Mesh Networks
Figure 12-31
Node 1
Node 11
PPMN also allows spans with different SONET speeds to be mixed together in "virtual rings."
Figure 12-32
backbone ring through OC-12 fiber. The "virtual ring" formed by Nodes 5, 6, 7, and 8 uses both OC-48
and OC-12 cards.
Cisco ONS 15454 Reference Manual, R8.5
12-32
Path-Protected Mesh Network
Node 2
Node 10
Protect traffic
Node 9
shows Nodes 1, 2, 3, and 4 in a standard OC-48 ring. Nodes 5, 6, 7, and 8 link to the
Chapter 12
Source
Node
Node 3
Node 4
Node 8
Node 7
Destination
Node
SONET Topologies and Upgrades
Node 5
Node 6
= Primary path
= Secondary path
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