Cisco Network Solutions for the Telco DCN:
SONET/SDH OSI Environments
This document is directed to competitive local exchange carriers (CLECs), incumbent local exchange
carriers (ILECs), and Post, Telephone and Telegraphs (PTTs), collectively referred to as telcos (short for
telephone companies). This document describes Cisco network solutions for transporting data between
Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) and the Operations
Support System (OSS) in a telco data communications network (DCN).
The DCN transports network management traffic between network elements and their respective OSS,
making them a vital link between the service network and the network operations center (NOC). The
solutions presented in this document will help telcos connect their SONET/SDH network elements to a
router-based network using the Open System Interconnection (OSI) protocol, which simplifies the DCN
and reduces equipment costs.
Version History
Version Number
Date
Notes
1
April 28, 2004
This document was created as a joint effort between Don
Schriner in the Cisco CTO Consulting Engineering Group
and Alliene Turner in Cisco IOS Documentation.
2
May 6, 2005
This document was updated.
3
January 3, 2008
This document was updated.
Contents
The document presents the recommended Cisco architecture for building the OSI network. Several
methods for implementing and scaling an OSI network are included with detailed configuration
examples. Specific Cisco IOS software features such as Intermediate System-to-Intermediate System
(IS-IS) multiareas, VLAN support for International Standards Organization Connectionless Network
Service (ISO CLNS), Target Identifier Address Resolution Protocol (TARP), and IS-IS attach bit control
are described. These architectures and software features are described in the following main sections:
•
Prerequisites, page 2
•
Scaling SONET/SDH in the Telco DCN:...