Cisco 15454-TCC - Network Processor Card Operation Manual page 392

Manual Circuit Routing
If you enabled Fully Path Protected, choose a diverse protect (alternate) path for every unprotected
•
segment (see
Figure A-3
Source
• For Multicard EtherSwitch circuits, the Fully Path Protected option is ignored.
• For a node that has a UPSR selector based on the links chosen, the input links to the UPSR selectors
cannot be 1+1 or BLSR protected (see
Figure A-4
UPSR
Node 1
(source)
Node 3
• Choose the links of Multicard EtherSwitch circuits in a shared packet ring to route from source to
destination back to source (see
invalid.
Cisco ONS 15454 Installation and Operations Guide
A-4
Figure A-3).
Alternate paths for virtual UPSR segments
UPSR UPSR
1+1
Node 1 Node 2
Node 3 Node 4
Twoway Twoway
Path Segment 1 Path Segment 2
UPSR/MESH 1+1 protected
protected
Needs alternate path
from N1 to N2
Mixing 1+1 or BLSR protected links with a UPSR
UPSR
Node 2
(destination)
BLSR ring
Node 4
UPSR
Illegal
Unprotected
Twoway Twoway
Node 5 Node 6
BLSR ring
Node 7 Node 8
Twoway
Path Segment 3
BLSR protected
No need for alternate path
Figure A-4). The same rule applies at the UPSR bridge.
Unprotected
UPSR
Unprotected
Node 1 Node 2
(source)
1+1 protected
Node 4
Node 3
(destination)
Unprotected
Illegal
Figure A-5). Otherwise, a route (set of links) chosen with loops is
Appendix A Circuit Routing
Node 9 Node 10
Node 11 Node 12
1+1 1+1
Twoway Twoway
Path Segment 4
1+1 protected
UPSR UPSR
Unprotected
Node 1 Node 2
(source)
Node 4
(destination)
Node 3
Unprotected
Legal
November 2001
Drop
Unprotected