Specifications

Cisco ONS 15454 Product Overview
Network Configuration
44
Cisco ONS 15454 Product Overview, R3.3
May 2002
Path-Protected Mesh Network
ONS 15454 networks give you the option of setting up path-protected mesh
networks (PPMNs). PPMN extends the protection scheme of UPSR from the basic
ring configuration to the meshed architecture of several interconnecting rings.
Typical UPSR protection creates two separate routes between source and
destination nodes on a single UPSR. PPMN does this for source and destination
nodes that do not lie on the same ring but link together through a network of
meshed connections. When applied to a single ring, PPMN uses the same paths as
the UPSR.
PPMN connects the source and destination of a circuit over two diverse paths
through a network of single or multiple meshed rings. These two paths form a
circuit-level UPSR. The source sends traffic on each of the diverse paths to the
destination node, where the destination node uses the active path or switches to
the standby path. CTC can automatically route circuits across the PPMN, or you
can manually route circuits.
Figure 28 shows an example of a PPMN. In the example, Node 3 is the source and
Node 9 is the destination. CTC automatically determines that the shortest route
between the two end nodes passes through Node 8 and Node 7, shown by the
dotted line. Cross-connections are automatically created at nodes 3, 8, 7, and 9 to
provide a working-traffic route.