Cisco ONS 15454 - Page 365

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Cisco ONS 15454 Reference Manual, R7.0.1
OL-9217-01
Chapter 11 Circuits and Tunnels
11.15 11.15 Manual Circuit Routing
Figure 11-10 Alternate Paths for Virtual Path Protection Segments
•
For multicard EtherSwitch circuits, the Fully Path Protected option is ignored.
• For a node that has a path protection selector based on the links chosen, the input links to the path
protection selectors cannot be 1+1 or BLSR protected (Figure 11-11). The same rule applies at the
path protection bridge.
Figure 11-11 Mixing 1+1 or BLSR Protected Links With a Path Protection
•
In a shared packet ring, choose the links of multicard EtherSwitch circuits to route from source to
destination back to source (Figure 11-12). Otherwise, a route (set of links) chosen with loops is
invalid.
55403
BLSR ring
1+1 1+1
1+1
Twoway Twoway
Twoway Twoway
Node 8Node 7
Node 5 Node 6
Unidirectional Unidirectional
TwowayTwoway
Node 4Node 3
Node 1 Node 2
Twoway
Node 12Node 11
Node 9 Node 10
Source
Path Segment 1
Path/MESH
protected
Needs alternate path
from N1 to N2
Drop
Path Segment 3
BLSR protected
Path Segment 2
1+1 protected
Path Segment 4
1+1 protected
No need for alternate path
55404
Unprotected
UnprotectedUnprotected
Unprotected
Unprotected
Unprotected
1+1 protected
BLSR ring
Node 4
(destination)
Node 3
nidirectional Unidirectional
Unidirectional Unidirectional
Unidirectional Unidirectional
Node 4Node 3
Node 1
(source)
Node 2
(destination)
Node 1
(source)
Node 2
Node 1
(source)
Node 2
Node 4
(destination)
Node 3
Illegal
Illegal
Unprotected
Legal