CHAPT ER
7-1
Cisco ONS 15310-MA SDH Reference Manual, Release 9.1 and Release 9.2
78-19417-01
7
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 15310-MA SDH synchronous transport signal (VC high-order path)
and Virtual Tributary (VC low-order path) circuits and VC low-order path and data communications
channel (DCC) tunnels. To provision circuits and tunnels, refer to the Cisco ONS 15310-MA SDH
Procedure Guide.
Chapter topics include:
7.1 Overview, page 7-1
7.2 Circuit Properties, page 7-2
7.3 VC-12 Bandwidth, page 7-8
7.4 VC Low-order Path Tunnels and Aggregation Points, page 7-8
7.5 DCC Tunnels, page 7-8
7.6 Subnetwork Connection Protection Circuits, page 7-9
7.7 Virtual Concatenated Circuits, page 7-11
7.8 Section and Path Trace, page 7-17
7.9 Bridge and Roll, page 7-18
7.10 Merged Circuits, page 7-22
7.11 Reconfigured Circuits, page 7-23
7.12 Server Trails, page 7-23

7.1 Overview

You can create circuits across and within ONS 15310-MA SDH nodes and assign different attributes to
circuits. For example, you can:
Create one-way, two-way (bidirectional), or broadcast circuits.
Assign user-defined names to circuits.