A Glossary of DSL Internet Access Terms and Definitions

It seems that so many industries today are following the trend of getting everything done faster. And that includes talking. So to get their talking done faster, they’ve created a vast index of acronyms. And the DSL industry is no exception.

So we’ve compiled this glossary of DSL Internet access terms and definitions – a simple list of the basics of DSL technology. The idea here isn’t to teach you a lot of technology. We just want you to have a basic understanding of DSL. So here they are:

• ADSL (Asymmetric Digital Subscriber Line)
  ADSL is a method for moving data over regular phone lines. An ADSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber's premises are the same (copper) wires used for regular phone service. ADSL allows a subscriber to download at higher speeds than they can upload.
• ATM (Asynchronous Transfer Mode)
  ATM refers to the actual ultra-high-speed data transmission protocol which may be run over ADSL.
• Bps (Bits per second)
  Bps is a measurement of the transmission speed of data.
• CO (Central Office)
  The CO is a circuit switch that terminates all the local access lines in a particular geographic serving area. It also refers to the physical building where the local switching equipment is found.
• CODEC
  CODEC is the abbreviation for a coder/decoder that converts a voice-grade analog signal to encoded samples. DSL bypasses the CODECs at the CO by separating the frequencies in a POTS splitter and passing the DSL signal to a DSLAM, the DSL equivalent of a CODEC.
• DSLAM (Digital Subscriber Line Access Multiplexer)
  A DSLAM is a device at the DSL provider end of the communication, which takes a number of ADSL subscriber lines and concentrates them to a single ATM line.
• DSL (Digital Subscriber Line)
  DSL is a system that provides subscribers with continuous, uninterrupted connections to the Internet over existing telephone lines, offering a choice of speeds ranging from 32 kbps (kilobits per second) to more than 50 mbps (megabits per second).
• DSL Lite
  DSL Lite is basically a slower ASDL that splits the line at the telephone company, rather than at the user end. It costs the user less, but reduces the maximum data rate.
• HDSL (High-data-rate Digital Subscriber Line)
  HDSL service was the earliest variation of DSL to be widely used. It provides equal bandwidth for both downloads and uploads, but requires multiple phone lines to accomplish this.
• ISP (Internet Service Provider)
  An ISP provides commercial access to the Internet.
• Kbps (Kilobits per second)
  Kbps is a measurement of the transmission speed of data.
• LAN (Local Area Network)
  LAN refers to a local computer network for communication between computers.
• Local Loop
  The local loop refers to a pair of wires, twisted for the entire length between the telephone company’s end office and the user’s telephone, thus forming a loop. This loop provides the user with access to the global telecommunications infrastructure that’s installed all over the world. DSL uses whatever frequencies that’ll transmit on this line for purposes of digital data transmission.
• Mbps (Megabits per second)
  Mbps is a measurement of the transmission speed of data.
• POTS (Plain Old Telephone Service)
  POTS is the only name recognized around the world for basic analog telephone service.
• Protocol
  Protocol is a formal description of message formats and the rules two computers must follow to exchange those messages. Protocols can describe low-level details of machine-to-machine interfaces (e.g., the order in which bits and bytes are sent across wire) or high-level exchanges between application programs (e.g., the way in which two programs transfer a file across the Internet).
• RADSL (Rate-Adaptive ADSL)
  RADSL is a version of ADSL where the modem tests the line at startup and adapts its operating speed to the fastest the line can handle.
• SDSL (Symmetric Digital Subscriber Line)
  SDSL, sometimes known as Single-line Digital Subscriber Line is a modified HDSL software technology that provides 1.5 Mbps in both directions over a single twisted pair. However, the distance over which this can be achieved is less than 8,000 feet.
• VADSL (Very-high-speed ASDL)
  VADSL is the same as VDSL.
• VDSL (Very-high-data Digital Subscriber Line)
  VDSL is a developing technology that promises much higher data rates over relatively short distances. It's thought that VDSL may emerge somewhat after ADSL is widely deployed and co-exist with it.
• WAN (Wide Area Network)
  A WAN is a private network facility, usually offered by public telephone companies, but increasingly available from alternative access providers that link businessnetworks.

You’ve seen this glossary of DSL Internet access terms and definitions. You’ve now armed yourself with the ammunition you need to order your DSL with confidence. You know what you need. You understand the terms. You’re now a qualified buyer!

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About The Author

Gareth Marples is a successful freelance writer providing tips and advice for consumers purchasing DSL modems, prepaid calling cards and web site hosting services. His numerous articles offer moneysaving tips and valuable insight on typically confusing topics.

This "Glossary of DSL Terms & Definitions" reprinted with permission.

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