Path-Protected Mesh Networks - Cisco ONS 15600 Series Reference Manual

Chapter 8 SONET Topologies and Upgrades
Figure 8-10 Connecting Fiber to a Four-Node, Four-Fiber BLSR
Node 1
Tx
Rx
West
Slot 2 Slot 3 Slot 12
Port 7 Port 1 Port 11
Tx
Rx
West
Slot 2 Slot 3 Slot 12
Port 7 Port 1 Port 11
Node 4

8.4 Path-Protected Mesh Networks

In addition to single BLSRs, path protectionconfigurations, and ADMs, you can extend ONS 15600
traffic protection by creating path-protected mesh networks (PPMNs). PPMNs include multiple
ONS 15600 SONET topologies and extend the protection provided by a single path protection to the
meshed architecture of several interconnecting rings. In a PPMN, circuits travel diverse paths through a
network of single or multiple meshed rings. When you create circuits, CTC automatically routes circuits
across the PPMN, or you can manually route them. You can also choose levels of circuit protection. For
example, if you choose full protection, CTC creates an alternate route for the circuit in addition to the
main route. The second route follows a unique path through the network between the source and
destination and sets up a second set of cross-connections.
For example, in
route between the two nodes passes through Node 8 and Node 7, shown by the dotted line, and
automatically creates cross-connections at Nodes 3, 8, 7, and 9 to provide the primary circuit path.
East West
Slot 13 Slot 2
Port 1 Port 7
East West
Slot 13 Slot 2
Port 1 Port 7
Figure 8-11, a circuit is created from Node 3 to Node 9. CTC determines that the shortest
Node 2
Tx
Rx
East
Slot 3 Slot 12 Slot 13
Port 1 Port 11 Port 1
Tx
Rx
East
Slot 3 Slot 12 Slot 13
Port 1 Port 11 Port 1
Node 3
Working fibers
Protect fibers
Cisco ONS 15600 Reference Manual, R7.0
8.4 Path-Protected Mesh Networks
8-11