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A-5
Cisco ONS 15454 Installation and Operations Guide
November 2001
Appendix A Circuit Routing
Manual Circuit Routing
Figure A-5
Ethernet shared packet ring routing
•
Multicard EtherSwitch circuits can have virtual UPSR segments if the source or destination is not
in the UPSR domain. This restriction also applies after circuit creation; therefore if you create a
circuit with UPSR segments, Ethernet node drops cannot exist anywhere on the UPSR segment (see
Figure A-6
).
Figure A-6
Ethernet and UPSR
•
VT Tunnels cannot be an endpoint of a UPSR segment. A UPSR segment endpoint is where the
UPSR selector resides.
If Fully Path Protected is chosen, CTC verifies that the route selection is protected at all segments. A
route can have multiple protection domains with each domain protected by a different mechanism.
The following tables summarize the available node connections. Any other combination is invalid and
will generate an error.
55405
Ethernet source
Ethernet destination
Node 4
Node 3
Node 1
Node 2
55406
UPSR Segment
Legal
Node 8
Node 7
Node 5
Node 2
Node 11
Node 11
Node 6
Source
Drop
UPSR Segment
Illegal
Node 8
Node 7
Node 5
Node 6
Source
Drop
Table A-1
Bidirectional STS/VT/Regular Multicard EtherSwitch/Point-to-Point (straight) Ethernet
Circuits
# of Inbound Links
# of Outbound Links
# of Sources
# of Drops
Connection Type
-
2
1
-
UPSR
2
-
-
1
UPSR
2
1
-
-
UPSR
1
2
-
-
UPSR
1
-
-
2
UPSR
-
1
2
-
UPSR
2
2
-
-
Double UPSR
2
-
-
2
Double UPSR