958 lines
24 KiB
HTML
958 lines
24 KiB
HTML
<HTML
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>Introduction</TITLE
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>DSL HOWTO for Linux</TH
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CLASS="SECT1"
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><H1
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CLASS="SECT1"
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><A
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NAME="INTRO">1. Introduction</H1
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><P
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> DSL, or Digital Subscriber Loop, is a high-speed Internet access technology
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that uses a standard copper telephone line (a.k.a. <SPAN
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CLASS="QUOTE"
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>"loop"</SPAN
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> in
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telco parlance). DSL provides a direct, dedicated connection to an ISP via
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the existing telco network. DSL is designed to run on up to 80% of the
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telephone lines available in the United States. By using line-adaptive
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modulation, DSL is capable of providing data speeds of 8 Mbps or more. </P
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><P
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> DSL services are now being aggressively marketed for home and small business
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use. DSL is typically priced below ISDN, and well below T1 service, yet can
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provide potentially even greater speeds than T1 without the
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cost, complexity, and availability issues of T1. Since DSL is a dedicated,
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often <SPAN
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CLASS="QUOTE"
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>"always on"</SPAN
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> service, it avoids the delays and use charges
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that are common with ISDN. Making this quite a nice technology for the
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bandwidth starved masses. </P
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><P
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> While all this sounds exciting, DSL does have some drawbacks. The quality of
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the DSL signal, and thus the connection, depends on distance (the length of
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the copper <SPAN
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CLASS="QUOTE"
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>"loop"</SPAN
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>) and various other factors. Also, there is no
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such thing as standard <SPAN
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CLASS="QUOTE"
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>"DSL"</SPAN
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>. There are various flavors of DSL,
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and many, many ways DSL providers are implementing their networks. In typical
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fashion, Linux users are often left to fend for themselves, since the DSL
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providers are often taking the easy way out, and catering only to
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<SPAN
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CLASS="QUOTE"
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>"mainstream"</SPAN
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> Operating Systems. </P
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><P
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> The topics included in this HOWTO include qualification and pre-installation,
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installation, configuration, troubleshooting and securing a DSL connection. As
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well as other related topics. There are also appendices including a
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comprehensive <A
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HREF="overview.html"
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>DSL Overview</A
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>, <A
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HREF="faq.html"
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>Frequently Asked Questions</A
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>, a listing of <A
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HREF="appendix.html#LINKS"
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>related links</A
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>, and a <A
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HREF="appendix.html#GLOSSARY"
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>glossary</A
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>. </P
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><P
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> Due to the fast pace of change in the telco and DSL industries, please make
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sure you have the latest version of this document. The current official
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version can always be found at
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<A
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HREF="http://www.tldp.org/HOWTO/DSL-HOWTO/"
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TARGET="_top"
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>http://www.tldp.org/HOWTO/DSL-HOWTO/</A
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>. Pre-release versions can be found at <A
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HREF="http://feenix.burgiss.net/ldp/adsl/"
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TARGET="_top"
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>http://feenix.burgiss.net/ldp/adsl/</A
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>. </P
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
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><A
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NAME="AEN83">1.1. Document Structure and Reading Guidelines</H2
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><P
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> This document attempts to give a comprehensive discussion of DSL. All aspects
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are hopefully addressed to one degree or another with what can be a complex
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topic since it deals with networking, hardware, new fangled technologies, and
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various approaches taken by various vendors. The core components of this
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document are:
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</P
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><P
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> <P
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></P
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><UL
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><LI
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><P
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> The <A
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HREF="installation.html"
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>Installation</A
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> section covers
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installation of DSL hardware and related components, including wiring
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considerations, splitter or microfilter installation, modem and Network
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card installation.
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</P
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></LI
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><LI
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><P
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> The <A
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HREF="configure.html"
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>Configuring Linux</A
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> section covers
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mostly client and software aspects of getting the connection up and
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running. The Network card configuration is actually covered mostly in the
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above Installation section.
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</P
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></LI
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><LI
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><P
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> The <A
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HREF="secure.html"
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>Securing Your Connection</A
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> section covers
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Security implications that are even more important with a full-time
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connection. Linux users seem especially targeted by crackers, because
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quite frankly, some don't understand how important security is, or don't
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understand the finer points of this. And who wants to <SPAN
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CLASS="QUOTE"
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>"own"</SPAN
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>
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a Windows box?
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</P
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></LI
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><LI
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><P
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> The <A
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HREF="tuning.html"
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>Tuning and Troubleshooting</A
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> section
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covers post-installation topics like how well is our connection performing,
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and how to track down any show-stoppers or intermittent problems.
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</P
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></LI
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><LI
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><P
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> There is also a lengthy Appendix that covers various topics relating to
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Linux and DSL. None of these are directly related to simply getting that
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connection up and running, but may be of interest nonetheless.
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</P
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></LI
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></UL
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></P
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><P
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> To simplify the navigation of this document, below is a suggested reading
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guideline. Everyone should read the Introduction. Please pay special
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attention to the <A
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HREF="intro.html#USAGE"
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>Conventions and Terminology</A
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>
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section, as some of this terminology may be used somewhat differently in
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other contexts. Also, there is a <A
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HREF="appendix.html#GLOSSARY"
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>Glossary</A
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> if
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you get lost in the world of TA (telco acronyms) ;-).
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</P
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><P
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> <P
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></P
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><UL
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><LI
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><P
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> If you don't know anything about DSL, you should probably read the entire
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document. You may want to start with the <A
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HREF="overview.html"
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>DSL
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Overview</A
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> section in the Appendix, and then the <A
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HREF="faq.html"
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>FAQ</A
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>. The DSL Overview explains how the various pieces
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of the puzzle fit together. DSL network implementations are more complex
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than traditional dialup networks.
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</P
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></LI
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><LI
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><P
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> If you have already done some homework, but have not ordered service from
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anyone yet, read the <A
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HREF="overview.html#CPROVIDERS"
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>Choosing
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Providers</A
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> section. Also, you might get a head start by reading the
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<A
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HREF="configure.html"
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>Configuring Linux</A
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> section so you know
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what lies ahead.
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</P
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></LI
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><LI
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><P
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> If you have ordered service already, and are awaiting delivery, you can
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skip the sections on choosing a Provider. If you will be doing a
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self-install, you should read the pertinent parts of the <A
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HREF="installation.html"
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>Installation</A
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> section, the <A
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HREF="configure.html"
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>Configuring Linux</A
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> section, and the <A
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HREF="secure.html"
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>Securing Your Connection</A
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> section.
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</P
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></LI
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><LI
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><P
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> If the installation is complete, and you can't get a working connection,
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skip right to the <A
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HREF="tuning.html"
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>Troubleshooting</A
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> Section.
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If you are not clear on what protocols are required, or what software you
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need to have installed, also read the <A
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HREF="configure.html"
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>Configuring Linux</A
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> section. If not sure what
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terms like <SPAN
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CLASS="QUOTE"
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>"sync"</SPAN
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> mean in this context, then be sure to read
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the <A
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HREF="overview.html"
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>DSL Overview</A
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> section first so you know
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how it all fits together.
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</P
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></LI
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><LI
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><P
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> If trying to decide between cable and DSL, read the
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<A
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HREF="appendix.html#CABLE"
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>Cable vs DSL</A
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> section, and possibly the
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<A
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HREF="overview.html"
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>DSL Overview</A
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> section.
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</P
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></LI
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><LI
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><P
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> If you have never had a full-time Internet connection, or are not
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absolutely sure you fully understand how to secure you connection,
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be sure to read The <A
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HREF="secure.html"
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>Securing Your Connection</A
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>
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section. If you don't understand some aspect of this, re-read it, or start
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looking for other references.
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</P
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></LI
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><LI
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><P
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> There is a comprehensive <A
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HREF="appendix.html#LINKS"
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>Links section</A
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> that
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has references to some topics not touched on in the main body of the
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Document itself.
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</P
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></LI
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></UL
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></P
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></DIV
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
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><A
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NAME="AEN137">1.2. What's New</H2
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><P
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> 1.71: Add info on the IteX PCI ADSL modem only. </P
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><P
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> 1.7: Added comments on ISDN line filters being different than POTS,
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and other additions related to ADSL over ISDN in various places. Add another
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supported modem: Eci Hi Focus ADSL Modem (and various related chipsets).
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Removed the 'Linux Friendly ISP' section. The landscape has changed much
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since this section was started. Back then there were few options for DSL in
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many places, and all too often a non-compatible modem was the only thing
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available. Also, the advent of microfilters and self-installation has helped
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with the <SPAN
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CLASS="QUOTE"
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>"do-it-yourselfer"</SPAN
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> approach, giving everybody more
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freedom. Then, maintaining this number of links was a PITA too. I still
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encourage new subscribers to shop their local markets if there are options.
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Many large ISPs and telcos have very poor ideas of what an Internet
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connection is and restrict severely what you can do with Linux. Or at least
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try to ;-) Updated LDP links to tldp.org (from linuxdoc.org).</P
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><P
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> 1.6: Several new Linux Friendly ISPs. Clarification on
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problems with alarm systems. Minor touch ups to other sections, and fix some
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broken links (never ending job :). </P
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><P
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> 1.5: New Tuning sub-section using <SPAN
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CLASS="APPLICATION"
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>iproute</SPAN
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>. Hot
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stuff! Other additions to the Tuning section. A few new ISPs. Alcatel
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SpeedTouch USB section updates. Thanks to Alex Bennee for clarifying things.
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Other minor updates to FAQ, Glossary and Tuning. </P
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><P
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> 1.4: A few new and updated URLs, and catch ups. The Alcatel USB modem section
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is revamped. A few new ISPs. </P
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><P
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> Version 1.3: Updates to the SpeedTouch USB HOWTO in the appendix.
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Minor update to PPPoE section, and two new Linux Friendly ISPs. A feeble
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attempt to make the document a little less U.S.-centric. Various minor
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updates.</P
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><P
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> Version 1.2 adds PPTP configuration section for Alcatel ethernet modems.
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Also, added are two additional sections in the <SPAN
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CLASS="QUOTE"
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>"Tuning"</SPAN
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> section
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for the TCP Receive window, and ADSL/DMT interleaving. And the big news is
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the release of open source drivers for the Alcatel USB modem as of March
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2001. There is an Alcatel SpeedTouch USB mini HOWTO in the <A
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HREF="speedtouchusb.html"
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>appendix</A
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> by Chris Jones. A number of
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miscellaneous updates as well.
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</P
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><P
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> Version 1.1 included quite a few minor corrections, updates,
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and additions. Not much that is substantially new. There are finally two
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Linux compatible DSL PCI modems from Xpeed. The drivers are now in the kernel
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2.2.18 source (not ported to 2.4 as of this writing 05/23/02).
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</P
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><P
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> Version .99 addresses some of the many changes that have occurred since the
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original ADSL mini HOWTO was published. Originally, ADSL was the primary DSL
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technology being deployed, but more and more some of the other DSL flavors
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are entering the picture -- IDSL, SDSL, G.Lite, and RADSL. Thus the renaming
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from <SPAN
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CLASS="QUOTE"
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>"ADSL mini HOWTO"</SPAN
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> to the <SPAN
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CLASS="QUOTE"
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>"DSL HOWTO"</SPAN
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>. There
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have been many other changes in DSL technology as well. PPPoE/A encapsulation
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has become more and more common as many ISPs are jumping on this bandwagon.
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</P
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></DIV
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
|
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><A
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NAME="AEN154">1.3. Copyright</H2
|
||
><P
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||
> DSL HOWTO for Linux (formerly the ADSL mini HOWTO)</P
|
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><P
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||
> Copyright <20> 1998,1999 David Fannin. </P
|
||
><P
|
||
> This document is free; you can redistribute it and/or modify it under the
|
||
terms of the GNU General Public License as published by the Free Software
|
||
Foundation; either version 2 of the License, or (at your option) any later
|
||
version.</P
|
||
><P
|
||
> This document is distributed in the hope that it will be useful, but WITHOUT
|
||
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
|
||
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
|
||
details.</P
|
||
><P
|
||
> You can get a copy of the GNU GPL at at <A
|
||
HREF="http://www.gnu.org/copyleft/gpl.html"
|
||
TARGET="_top"
|
||
>GNU GPL</A
|
||
>.</P
|
||
></DIV
|
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><DIV
|
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CLASS="SECT2"
|
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><H2
|
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CLASS="SECT2"
|
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><A
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NAME="AEN162">1.4. Credits</H2
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><P
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||
> Thanks to all those that contributed information to this HOWTO. I have
|
||
anti-spammed their email addresses for their safety (and mine!). Remove the
|
||
X's from their names.</P
|
||
><P
|
||
> <P
|
||
></P
|
||
><UL
|
||
><LI
|
||
><P
|
||
> <EM
|
||
>B Ediger</EM
|
||
> (Xbediger@csn.net) Great
|
||
Description of loop impairment.
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <EM
|
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>C Wiesner</EM
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||
> ( Xcraig@wkmn.com) List of many ADSL URLs.
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <EM
|
||
>J Leeuw</EM
|
||
> ( Xjacco2@dds.nl) Many tips on ADSL,
|
||
especially in Europe
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <EM
|
||
>N Silberstein</EM
|
||
> ( Xnick@tpdinc.com) Info on
|
||
Netrunner and his experience with US Worst.
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> Many and various posters from comp.dcom.xdsl and
|
||
bellsouth.net.support.adsl, too numerous to mention individually.
|
||
(HB)
|
||
</P
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||
></LI
|
||
><LI
|
||
><P
|
||
> <EM
|
||
>Juha Saarinen</EM
|
||
> for suggestions and
|
||
explanations on the TCP Receive Window, and related tuning topics.
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <EM
|
||
>Chris Jones</EM
|
||
>
|
||
<TT
|
||
CLASS="EMAIL"
|
||
><<A
|
||
HREF="mailto:chris@black-sun.co.uk"
|
||
>chris@black-sun.co.uk</A
|
||
>></TT
|
||
> for his Alcatel SpeedTouch USB mini
|
||
HOWTO which was previously incorporated into the <A
|
||
HREF="speedtouchusb.html"
|
||
>Appendix</A
|
||
>. Also, Alex Bennee for clarifying
|
||
the driver situation for this modem.
|
||
</P
|
||
></LI
|
||
></UL
|
||
></P
|
||
></DIV
|
||
><DIV
|
||
CLASS="SECT2"
|
||
><H2
|
||
CLASS="SECT2"
|
||
><A
|
||
NAME="DISCLAIMER">1.5. Disclaimer</H2
|
||
><P
|
||
> The authors accept no liability for the contents of this document. Use the
|
||
concepts, examples and other content at your own risk. As this is a new
|
||
edition, there may be errors and inaccuracies. Hopefully these are few and
|
||
far between. The author(s) do not accept any responsibility for incorrect or
|
||
misleading information, and would certainly appreciate any corrections. Also,
|
||
this type of technology dates itself very quickly. What may be true today, is
|
||
not guaranteed to be true tomorrow. </P
|
||
><P
|
||
> All copyrights are held by their respective owners, unless specifically noted
|
||
otherwise. Use of a term in this document should not be regarded as affecting
|
||
the validity of any trademark or service mark. </P
|
||
><P
|
||
> References to any particular product, brand, service or company should
|
||
not be construed as an endorsement or recommendation. Excepting Linux
|
||
itself, of course! </P
|
||
></DIV
|
||
><DIV
|
||
CLASS="SECT2"
|
||
><H2
|
||
CLASS="SECT2"
|
||
><A
|
||
NAME="AEN194">1.6. Feedback</H2
|
||
><P
|
||
> Any and all comments on this document are most welcomed. Please make sure you have
|
||
the most current version before submitting corrections! These can be sent to
|
||
<TT
|
||
CLASS="EMAIL"
|
||
><<A
|
||
HREF="mailto:hal@foobox.net"
|
||
>hal@foobox.net</A
|
||
>></TT
|
||
></P
|
||
></DIV
|
||
><DIV
|
||
CLASS="SECT2"
|
||
><H2
|
||
CLASS="SECT2"
|
||
><A
|
||
NAME="USAGE">1.7. Conventions, Usage and Terminology</H2
|
||
><P
|
||
> For the sake of simplicity and sanity, let's clarify some of the terminology
|
||
that we will be using in this document, so that we are all on the same page.
|
||
While many of the definitions below are not always 100% technically correct,
|
||
they are close enough for our purposes here. In fast moving technologies like
|
||
DSL, there are so many <SPAN
|
||
CLASS="QUOTE"
|
||
>"ifs, ands, and buts"</SPAN
|
||
> that it is
|
||
difficult to say anything with any degree of certainty and have it stick. And
|
||
there are exceptions to almost every rule. And sometimes exceptions to the
|
||
exceptions. We will be dealing with generalities to a large degree here,
|
||
please keep that in mind. </P
|
||
><P
|
||
> <P
|
||
></P
|
||
><UL
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"DSL"</SPAN
|
||
> will be used to refer to the entire family of DSL
|
||
technologies now available -- ADSL, SDSL, IDSL, RADSL, etc. ADSL still
|
||
seems to be the most prevalent at this time, but the others are being
|
||
deployed as well. Where it is important to differentiate one type of
|
||
DSL from another, the full proper name will be used: e.g. RADSL. xDSL is
|
||
also commonly used to refer to the various DSL technologies as a group, but
|
||
we will be using just <SPAN
|
||
CLASS="QUOTE"
|
||
>"DSL"</SPAN
|
||
> here.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> The term <SPAN
|
||
CLASS="QUOTE"
|
||
>"telco"</SPAN
|
||
> here refers to any potential DSL provider.
|
||
This includes the ILECs (Incumbent Local Exchange Carriers), a.k.a. the old
|
||
guard phone companies or state run phone companies, and where the
|
||
monopolies now have competition, the CLECs (Competitive Local Exchange
|
||
Carriers), or independent providers such as Covad in the U.S.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"CO"</SPAN
|
||
> is the telco acronym for <SPAN
|
||
CLASS="QUOTE"
|
||
>"Central Office"</SPAN
|
||
>.
|
||
Traditionally this is a building where one end of your phone line
|
||
physically terminates. The other end terminates at your home, office, or
|
||
wherever. It will be used here to refer to the telco end termination point,
|
||
regardless of whether it is a traditional Central Office building or
|
||
another, smaller, remote structure or device.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"Loop"</SPAN
|
||
> is telco speak for <SPAN
|
||
CLASS="QUOTE"
|
||
>"phone line"</SPAN
|
||
>.
|
||
Essentially, you should think of your loop as one dedicated pair of copper
|
||
wires that run uninterrupted from your residence or office directly to the
|
||
CO. This is perhaps an oversimplification, but will serve our purposes. DSL
|
||
availability, and signal quality, is tied directly to the characteristics
|
||
of your physical line -- or <SPAN
|
||
CLASS="QUOTE"
|
||
>"loop"</SPAN
|
||
> as they say.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"POTS"</SPAN
|
||
> is the acronym for Plain Old Telephone Service. In other
|
||
words, traditional, non-digital devices like analog phones, faxes and answering
|
||
machines. ISDN is used for DSL in some areas, so POTS is not the only way
|
||
to piggy-back DSL. But certainly the most common in many places.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"NID"</SPAN
|
||
>, or Network Interface Device, is the small telco
|
||
housing that is often typically attached to the outside wall of your house,
|
||
and is the service entrance for telco services, though may be placed
|
||
elsewhere depending on the phone company. This may variously also be
|
||
referred to as <SPAN
|
||
CLASS="QUOTE"
|
||
>"ONI"</SPAN
|
||
>, <SPAN
|
||
CLASS="QUOTE"
|
||
>"SNI"</SPAN
|
||
>, <SPAN
|
||
CLASS="QUOTE"
|
||
>"NIU"</SPAN
|
||
>,
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"TNI"</SPAN
|
||
> or other creative telco acronyms. It represents the
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"demarcation"</SPAN
|
||
> point that divides the customer's realm of
|
||
responsibility from the telco's. Commercial structures, and multi-family
|
||
housing will likely have something more sophisticated, and probably located
|
||
inside somewhere.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"DSLAM"</SPAN
|
||
> is the sophisticated hardware device in the telco's CO
|
||
where your phone line physically terminates, and thus makes DSL happen.
|
||
Increasingly, telcos are making use of smaller devices like the
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"mini-RAM"</SPAN
|
||
> in remote locations. We'll use <SPAN
|
||
CLASS="QUOTE"
|
||
>"DSLAM"</SPAN
|
||
>
|
||
here as a catch-all for any device that enables DSL service from a telco.
|
||
These are now being manufactured by a number of companies.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> <SPAN
|
||
CLASS="QUOTE"
|
||
>"Modem"</SPAN
|
||
> will be used to refer to the end user device that
|
||
enables a DSL connection. Your <SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
> is connected to the
|
||
telco's DSLAM in the CO via your copper loop. When they are
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"talking"</SPAN
|
||
> DSL to each other, they are in <SPAN
|
||
CLASS="QUOTE"
|
||
>"sync"</SPAN
|
||
>.
|
||
Without <SPAN
|
||
CLASS="QUOTE"
|
||
>"sync"</SPAN
|
||
>, no connection to your ISP is possible.
|
||
|
||
</P
|
||
><P
|
||
>
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"Modem"</SPAN
|
||
> is indeed the correct terminology since there is
|
||
MOdulation and DEModulation of the signal, even though it doesn't
|
||
resemble an analog 56K modem like many of us have had before. These modems
|
||
incorporate other features too -- so they are more than just a
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
>. Some ISPs and manufacturers may be marketing simply
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"routers"</SPAN
|
||
>, <SPAN
|
||
CLASS="QUOTE"
|
||
>"bridges"</SPAN
|
||
>, or even
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"brouters"</SPAN
|
||
> for this purpose. These are essentially DSL modems
|
||
with enhancements. A compatible <SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
> of some kind is the
|
||
minimum hardware requirement at the customer's end of the connection. The
|
||
most commonly supplied modem is actually a combination bridge and modem.
|
||
</P
|
||
><P
|
||
> One distinction here may be where ADSL is provided over ISDN lines. In this
|
||
case, the term <SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
> is not appropriate and the only
|
||
physical difference is that the ISDN Network Terminator (NT), is equipped
|
||
to handle DSL, but is still an NT. In any case, for brevity, we will take
|
||
license here to refer to all such devices as <SPAN
|
||
CLASS="QUOTE"
|
||
>"modems"</SPAN
|
||
>.
|
||
</P
|
||
><P
|
||
> Unless stated otherwise, we will also be assuming the <SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
>
|
||
has an ethernet interface, and will connect to a standard ethernet Network
|
||
Card (NIC). This is far and away the most prevalent configuration for Linux
|
||
users, at least until more Linux drivers are available for PCI and USB
|
||
modems. USB modem are quite popular otherwise, because they are
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"plug 'n play"</SPAN
|
||
>, and arguably less expensive.
|
||
|
||
</P
|
||
><P
|
||
> It is worth noting that <SPAN
|
||
CLASS="QUOTE"
|
||
>"routers"</SPAN
|
||
> as supplied by DSL providers
|
||
are typically modem/router combination devices. In our context,
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"router"</SPAN
|
||
> will refer to these devices as such. There are also
|
||
SOHO broadband routers available that are only dedicated routers and lack
|
||
the modem functionality.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> Previous versions of this document referred to the modem as an
|
||
<SPAN
|
||
CLASS="QUOTE"
|
||
>"ANT"</SPAN
|
||
> (ADSL Network Termination). While this may be
|
||
technically correct terminology, it is not used by ISPs, manufacturers,
|
||
telcos, or most users to any extent. The <SPAN
|
||
CLASS="QUOTE"
|
||
>"modem"</SPAN
|
||
> will be just
|
||
called a modem, regardless of whatever other features it may incorporate (i.e.
|
||
router, bridge, etc.).
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> PPPoX will be used to refer to PPPoE (PPP over Ethernet) and PPPoA
|
||
(PPPoATM, or PPP over ATM) collectively. These protocols are being used by
|
||
many DSL providers now.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> The information provided in this document is based mostly on the current
|
||
state of DSL in the U.S. I will assume there are enough similarities with
|
||
DSL services outside of the US that this document would still have some
|
||
merit for everyone. Correct me if I am wrong by emailing
|
||
<TT
|
||
CLASS="EMAIL"
|
||
><<A
|
||
HREF="mailto:hal@foobox.net"
|
||
>hal@foobox.net</A
|
||
>></TT
|
||
>.
|
||
|
||
</P
|
||
></LI
|
||
><LI
|
||
><P
|
||
> A <SPAN
|
||
CLASS="QUOTE"
|
||
>"#"</SPAN
|
||
> will be used to denote a command that typically is run
|
||
by the root user. Otherwise, a <SPAN
|
||
CLASS="QUOTE"
|
||
>"$"</SPAN
|
||
> will be used as the prompt
|
||
for non-root users.
|
||
|
||
</P
|
||
></LI
|
||
></UL
|
||
></P
|
||
></DIV
|
||
></DIV
|
||
><DIV
|
||
CLASS="NAVFOOTER"
|
||
><HR
|
||
ALIGN="LEFT"
|
||
WIDTH="100%"><TABLE
|
||
SUMMARY="Footer navigation table"
|
||
WIDTH="100%"
|
||
BORDER="0"
|
||
CELLPADDING="0"
|
||
CELLSPACING="0"
|
||
><TR
|
||
><TD
|
||
WIDTH="33%"
|
||
ALIGN="left"
|
||
VALIGN="top"
|
||
><A
|
||
HREF="index.html"
|
||
ACCESSKEY="P"
|
||
>Prev</A
|
||
></TD
|
||
><TD
|
||
WIDTH="34%"
|
||
ALIGN="center"
|
||
VALIGN="top"
|
||
><A
|
||
HREF="index.html"
|
||
ACCESSKEY="H"
|
||
>Home</A
|
||
></TD
|
||
><TD
|
||
WIDTH="33%"
|
||
ALIGN="right"
|
||
VALIGN="top"
|
||
><A
|
||
HREF="installation.html"
|
||
ACCESSKEY="N"
|
||
>Next</A
|
||
></TD
|
||
></TR
|
||
><TR
|
||
><TD
|
||
WIDTH="33%"
|
||
ALIGN="left"
|
||
VALIGN="top"
|
||
>DSL HOWTO for Linux</TD
|
||
><TD
|
||
WIDTH="34%"
|
||
ALIGN="center"
|
||
VALIGN="top"
|
||
> </TD
|
||
><TD
|
||
WIDTH="33%"
|
||
ALIGN="right"
|
||
VALIGN="top"
|
||
>Installation</TD
|
||
></TR
|
||
></TABLE
|
||
></DIV
|
||
></BODY
|
||
></HTML
|
||
> |