Appendix; Circuit Routing; Automatic Circuit Routing; Figure A-1 Multiple Protection Domains - Cisco 15454-TCC - Network Processor Card Operation Manual

Circuit Routing

This appendix provides an in-depth explanation of ONS 15454 circuit routing and VT tunneling in mixed
protection or meshed environments, such as the one shown in
provisioning procedures, see
Figure A-1
Source

Automatic Circuit Routing

If you select automatic routing during circuit creation, Cisco Transport Controller (CTC) routes the
circuit by dividing the entire circuit route into segments based on protection domains. For unprotected
segments of protected circuits, CTC finds an alternate route to protect the segment in a virtual UPSR
fashion. Each path segment is a separate protection domain, and each protection domain is protected in
a specific fashion (virtual UPSR, BLSR, or 1+1).
November 2001
Chapter 6, "Circuits and Tunnels."
Multiple protection domains
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
Primary path
Alternate path
A P P E N D I X
Figure
Twoway Twoway
Node 5 Node 6
BLSR ring
Node 7 Node 8
1+1
Twoway
Path Segment 3
BLSR protected
Cisco ONS 15454 Installation and Operations Guide
A
A-1. For circuit creation and
Node 9 Node 10
Node 11 Node 12
1+1
Twoway Twoway
Path Segment 4
1+1 protected
Drop
A-1