Chapter 8 Sonet Topologies And Upgrades; Overview; Point-To-Point And Linear Adm Configurations - Cisco ONS 15600 Reference Manual

SONET Topologies and Upgrades
The terms "Unidirectional Path Switched Ring" and "UPSR" may appear in Cisco literature. These terms
Note
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 15600 SONET topologies and upgrades. To provision topologies, refer
to the Cisco ONS 15600 Procedure Guide.
Chapter topics include:
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8.1 Overview

The ONS 15600 usually operates as a hub node in networks that include ONS 15454s, ONS 15327s, and
ONS 15310-CLs. Single nodes are installed at geographic locations where several ONS SONET
topologies converge. A single ONS 15600 node might be a part of several ONS SONET rings/networks.
To avoid errors during network configuration, Cisco recommends that you draw the complete
ONS SONET network topology on paper (or electronically) before you begin the physical
implementation. A sketch ensures that you have adequate slots, cards, and fibers to complete the
topology.

8.2 Point-to-Point and Linear ADM Configurations

You can configure ONS 15600s as a line of add/drop multiplexers (ADMs) by configuring one OC-N
port as the working path and a second port as the protect path. Unlike rings, point-to-point (two node
configurations) and linear (three node configurations) ADMs require that the OC-N ports at each node
be in 1+1 protection to ensure that a break to the working line is automatically routed to the protect line.
8.1 Overview, page 8-1
8.2 Point-to-Point and Linear ADM Configurations, page 8-1
8.3 Bidirectional Line Switched Rings, page 8-2
8.4 Path-Protected Mesh Networks, page 8-11
8.5 In-Service Topology Upgrades, page 8-13
C H A P T E R
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