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4351 - DSL Source Book
TABLE OF CONTENTS
Foreword
Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Preface
- About this Sourcebook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Chapter 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Chapter 2
The Existing Copper Wire Infrastructure. . . . . . . . . . . . . 2-1
Telephone Company Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
The Access Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Dedicated T1/E1 Access Using the Local Loop Network . . . . . . . . 2-4
Private/Campus Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Chapter 3
DSL Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Basic DSL Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Attenuation and Resulting Distance Limitations . . . . . . . . . . . . . . . 3-1
Advanced Modulation Techniques Minimize Attenuation . . . . . . . . 3-2
The Effects of Crosstalk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Asymmetry Allows Us to Leverage the Environment . . . . . . . . . . . . 3-7
Continuing Developments in DSL . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Chapter 4
DSL System Components. . . . . . . . . . . . . . . . . . . . . . . . 4-1
Adding Data to the Traditional Voice Network . . . . . . . . . . . . . . . . 4-1
DSL-based Services & Components . . . . . . . . . . . . . . . . . . . . . . . . 4-2
A Word About Smart DSLAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
End-to-End Network Management Component . . . . . . . . . . . . . . . 4-7
But This Isnt The Whole Story . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Chapter 5
Market Evolution & Deployment Realities . . . . . . . . . . . 5-1
Market Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Deployment Statistics to Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Deployment Realities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
The New Regulatory Environment. . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Chapter 6
Emerging Services and Applications . . . . . . . . . . . . . . . . 6-1
An Access Technology for the 90s . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Channelized T1/E1 Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
IP Services - The Arrival of Internet-based Networking . . . . . . . . . . 6-3
Frame Relay Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Frame Relay Over DSL and Service Level Management . . . . . . . . . . 6-8
Asynchronous Transfer Mode Services . . . . . . . . . . . . . . . . . . . . . 6-10
Campus/Private Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
The Next Wave: Voice Over DSL Services. . . . . . . . . . . . . . . . . . . 6-11
© Copyright 2000
Paradyne Corporation
DSL-BOOK-3.0-0900
Paradyne, Hotwire and FrameSaver are registered trademarks of Paradyne Corporation. MVL, OpenLane and Hotwire Connected are trademarks of Paradyne
Corporation. All other products or services mentioned are the trademarks, service marks, registered trademarks or registered service marks of their respective owners. Chapter 7
Network Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
The Need for Multiservices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
DSL-based Services Reference Model . . . . . . . . . . . . . . . . . . . . . . . 7-1
Frame Relay Services Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Nx64 Services Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
IP/LAN Services Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Layer 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Layer 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
ATM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
An Overview of Issues for IP/LAN Services . . . . . . . . . . . . . . . . . . 7-9
A Word about Virtual Private Networks . . . . . . . . . . . . . . . . . . . . 7-10
ATM Services Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
Multiservices Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Chapter 8
Sourcebook in Review . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
In Closing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Considerations for DSL Deployment Initiative . . . . . . . . . . . . . . . . 8-1
Common Questions and Answers About DSL. . . . . . . . . . . . . . . . . 8-2
About Paradyne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
DSL Sourcebook Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 FOREWORD
WELCOME
To the fast-paced, exciting (and sometimes confusing) world of DSL (Digital Subscriber
Line) technology. While many broadband access methods are gunning for ownership of the
local loop, you are about to learn that DSL technology has a distinct advantage that makes
it one of the most viable options for the delivery of high-speed data services.
Unlike competing technologies, DSL eliminates the need for extensive and expensive infra-
structure upgrades improvements that are hard to measure in terms of time or money.
Where original telephone company strategies centered on the time-consuming and costly
task of fiber installation, demand for multimegabit services has forced them to evaluate
approaches that leverage the existing infrastructure and provide a quicker time to market.
That is one of DSL technologys chief advantages the ability to transform the nearly 700
million phone lines installed worldwide into multimegabit data pipes capable of speeding
digital voice and data to homes and businesses.
That ability has ignited the market, as telephone companies, PTTs, Interexchange Carriers
(IXCs) and Competitive Local Exchange Carriers (CLECs) alike move to evaluate and imple-
ment this exciting new technology. Today, nearly every major service provider worldwide is
using or trialing one form of DSL or another. The over-hyped information age is truly upon
us as the aging copper plant continues its transformation into high-speed broadband net-
works. New, advanced applications surface almost daily, and expectations remain high that a
host of new services and tools to guarantee performance of those new services will be
launched thanks to DSL.
DSLs enormous promise has worked the telecommunications industry into a frenzy, seem-
ingly overnight. As a cursory survey of the market shows, the amount of information and
misinformation on this topic is astounding. Wading through the alphabet soup of acronyms
and sorting through DSL fact and fiction is certainly time consuming. But DSLs big band-
width payoff is truly worth that time. That is where The DSL Sourcebook The Comprehensive
Resource on Digital Subscriber Line Technology comes in. This Third Edition will focus on the
state of the DSL evolution and examine emerging market requirements such as automated,
flow-through provisioning, and end-to-end services delivery and management these are
bound to be the next great frontier in DSL.
Service providers and service users who become familiar with the growing family of DSL
technologies can avoid potential pitfalls by effectively matching the appropriate DSL trans-
port to the application at hand. This book will help to level out the steep DSL learning curve
and reduce the time it takes to select and implement the best technology for your given
application.
While there are many hurdles in implementing any new technology, this book will help to
speed you on in leveraging the hottest transport to hit the local loop in years.
Paradyne, a leader in the DSL equipment market, and TeleChoice, a leader in consulting
services, are proud to bring you this concise and informative Sourcebook.
Patrick Hurley
Broadband Consultant
TeleChoice, Inc.
A-1 PREFACE
ABOUT THE SOURCEBOOK
The copper wire telephone infrastructure is everywhere. If you want to understand how you
can turn existing copper into high-speed network access links, this book is for you. We wrote
The DSL Sourcebook The Comprehensive Resource on Digital Subscriber Line Technology to
assist you in making informed choices about this exciting new market. DSL technology is
quickly gaining recognition and acceptance as a viable way to meet the ever-increasing
demand for more bandwidth. As the Internet continues to evolve into a global on-line inter-
face supporting multiple media types (data, audio and video), the bandwidth demand will
continue to soar.
DSL-based services are not just about speed, nor about the explosive growth of the Internet.
DSL-based services are about applications and opportunities. DSL technology offers a win-
win scenario for both those who provision high-speed, value-added services and for the users
of those serv