Introduction
EN/LZT 108 6429 R1 5 (47)
May 2003
1 Introduction

1.1 About this Guide

This User Guide provides general information about the installation of the Ericsson
ADSL Modem HM121dp/di in a PC/Windows environment, as well as information
about day-to-day use of the modem.
You can learn more about unfamiliar or technical terms by consulting the "Glossary"
in this guide.
The following chapters are included in this guide:
•Chapter 1 - "Introduction" provides features of the HM121dp/di as well as a brief
description of ADSL and protocol and device driver selection.
•Chapter 2 - "Installation Procedure" describes the steps for installing and
connecting the HM121dp/di in a PC/Windows environment.
•Chapter 3 - "Accessing the Internet" provides instructions about how to access
the Internet when using either the LAN or WAN device driver.
•Chapter 4 - "Verifying your ADSL Connection" describes how to use the ADSL
Modem icon and the Control Panel of the modem to configure and check the
performance of the HM121dp/di and the ADSL connection.
•Chapter 5 - "Customizing Communication Settings" provides steps for altering
the ATM Virtual Path ID (VPI), ATM Virtual Circuit ID (VCI), Encapsulation
type and/or Modulation type values previously defined.
•Chapter 6 - "Uninstalling and Updating Modem Software" describes the
procedure for uninstalling the modem software and also how to update to a new
version of the modem software.
•Chapter 7 - "Troubleshooting" provides information about how to verify your
modem installation and also some tips and solutions for resolving some of the
problems that might encounter while installing or using your modem.
•Chapter 8 - "Important Information" provides information about License
Agreement and Regulatory Information.
•The "Glossary" includes abbreviations and explanations to technical terms used in
this guide.

1.2 About ADSL

The ADSL (Asymmetric Digital Subscriber Line) technology provides high-speed
data access across regular phone lines (copper wires) by making use of previously
unused frequency bandwidth above the voice band. By placing the ADSL signal
above the frequency of the voice signal, ADSL service is able to coexist on the same
line with your telephone service. ADSL is symmetric in the sense that it provides a
higher data rate in the downstream (receive) direction than in the upstream (transmit)
direction. Asymmetric operation is ideal for typical home and small office use where
files and information are downloaded more frequently than uploaded.
The HM121dp/di is capable of supporting the following DSL standards: ANSI T1.413
Issue 2, ITU G.992.1 (G.DMT), ITU G.992.2 (G.lite), and ITU G.992 Annexes A, B
and C as applicable.