Cisco ONS 15454 SDH Manual page 22

11.14 Manual Circuit Routing
Figure 11-7
Source
•
•
Figure 11-8 Mixing 1+1 or MS-SPRing Protected Links with an SNCP
SNCP
Node 1
(source)
Node 3
•
Cisco ONS 15454 SDH Reference Manual, R8.5
11-22
Alternate Paths for Virtual SNCP Segments
SNCP SNCP
Node 1 Node 2
Node 3 Node 4
Two way Two way
Path Segment 1 Path Segment 2
SNCP/mesh 1+1 protected
protected
Needs alternate path
from N1 to N2
For multicard EtherSwitch circuits, the Fully Path Protected option is ignored.
For a node that has an SNCP selector based on the links chosen, the input links to the SNCP selectors
cannot be 1+1 or MS-SPRing protected
SNCP
Node 2
(destination)
MS-SPRing
Node 4
Illegal
Unprotected
Choose the links of multicard EtherSwitch circuits in a shared packet ring to route the circuit from
source to destination back to source
loops is invalid.
Two way Two way
1+1
Node 5 Node 6
MS-SPRing
Node 7 Node 8
Two way
Path Segment 3
MS-SPRing protected
No need for alternate path
(Figure 11-8). The same rule applies at the SNCP bridge.
SNCP SNCP
Unprotected
Node 1 Node 2
(source)
1+1 protected
Node 4
Node 3
(destination)
Unprotected
Illegal
(Figure 11-9). Otherwise, a route (set of links) chosen with
Chapter 11 Circuits and Tunnels
Node 9 Node 10
Node 11 Node 12
1+1 1+1
Two way
Path Segment 4
1+1 protected
SNCP
Unprotected
Node 1 Node 2
(source)
Unprotected
Node 4
(destination)
Node 3
Unprotected
Legal
Drop
Two way
SNCP
Unprotected
78-18119-01