user manual

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Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 11 SDH Topologies and Upgrades
11.7 Extended SNCP Mesh Networks
Figure 11-28 Linear (Point-to-Point) ADM Configuration
11.7 Extended SNCP Mesh Networks
In addition to single MS-SPRings, SNCP rings, and ADMs, you can extend ONS 15454 SDH traffic
protection by creating extended SNCP mesh networks. Extended SNCP rings include multiple
ONS 15454 SDH topologies and extend the protection provided by a single SNCP ring to the meshed
architecture of several interconnecting rings.
In an extended SNCP ring, circuits travel diverse paths through a network of single or multiple meshed
rings. When you create circuits, you can provision CTC to automatically route circuits across the
Extended SNCP ring, 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 Figure 11-29, a circuit is created from Node 3 to Node 9. CTC determines that the
shortest 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.
If full protection is selected, CTC creates a second unique route between Nodes 3 and 9 which, in this
example, passes through Nodes 2, 1, and 11. Cross-connections are automatically created at Nodes 3, 2,
1, 11, and 9, shown by the dashed line. If a failure occurs on the primary path, traffic switches to the
second circuit path. In this example, Node 9 switches from the traffic coming in from Node 7 to the
traffic coming in from Node 11 and service resumes. The switch occurs within 50 ms.
Node 1 Node 3 Node 2
Slot 5 to Slot 5
Slot 6 to Slot 6
Slot 12 to Slot 12
Slot 13 to Slot 13
Working Path
Protect Path
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