CHAPT ER
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Cisco ONS 15454 Reference Manual, R7.0
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11
Circuits and Tunnels
Note The terms "Unidirectional Path Switched Ring" and "UPSR" may appear in Cisco literature. These terms
do not refer to using Cisco ONS 15xxx products in a unidirectional path switched ring configuration.
Rather, these terms, as well as "Path Protected Mesh Network" and "PPMN," refer generally to Cisco's
path protection feature, which may be used in any topological network configuration. Cisco does not
recommend using its path protection feature in any particular topological network configuration.
This chapter explains Cisco ONS 15454 synchronous transport signal (STS), virtual tributary (VT), and
virtual concatenated (VCAT) circuits and VT, data communications channel (DCC), and IP-encapsulated
tunnels. To provision circuits and tunnels, refer to the Cisco ONS 15454 Procedure Guide.
Chapter topics include:
• 11.1 Overview, page 11-2
• 11.2 Circuit Properties, page 11-2
• 11.3 Cross-Connect Card Bandwidth, page 11-12
• 11.4 Portless Transmux, page 11-15
• 11.5 DCC Tunnels, page 11-16
• 11.6 SDH Tunneling, page 11-18
• 11.7 Multiple Destinations for Unidirectional Circuits, page 11-18
• 11.8 Monitor Circuits, page 11-19
• 11.9 Path Protection Circuits, page 11-19
• 11.10 BLSR Protection Channel Access Circuits, page 11-21
• 11.11 BLSR STS and VT Squelch Tables, page 11-22
• 11.12 Section and Path Trace, page 11-23
• 11.13 Path Signal Label, C2 Byte, page 11-24
• 11.14 Automatic Circuit Routing, page 11-26
• 11.15 Manual Circuit Routing, page 11-28
• 11.16 Constraint-Based Circuit Routing, page 11-32
• 11.17 Virtual Concatenated Circuits, page 11-33
• 11.18 Bridge and Roll, page 11-37
• 11.19 Merged Circuits, page 11-42