Various Types of DSL Broadband Internet Connections

Table of Content

  1. Overview of DSL
  2. Types of DSL Technologies
  3. Disadvantages of DSL
  4. Should I Get DSL?
  5. Summary

Overview of DSL

There are a variety of flavors when it comes to Digital Subscriber Line (DSL) broadband Internet connection. DSL is a technology that brings high bandwidth Internet connection to homes and businesses over ordinary copper telephone lines. DSL technology allows data transmission at speeds much faster than the best available analog and digital modems. In general, most DSL connections offer download speeds between 5 to 35Mbps and upload speeds between 1 to 10Mbps. We'll explain a few of the variety of DSL connections below.

Types of DSL Technologies

DSL is a generic term used for a family of related technologies, including RADSL, ADSL, SDSL, IDSL, and others. The leading DSL technologies being deployed today include:

RADSL - (Rate Adaptive Digital Subscriber Line)

  • Most robust business DSL available today;
  • Developed to overcome line impediments;
  • Automatically adjusts for environmental conditions; - Because RADSL is a type of SDSL, it supports symmetric (equal downstream and upstream) data transmissions up to 768K.

ADSL - Asymmetrical Digital Subscriber Line
ADSL supports a range of asymmetric (higher downstream than upstream) data speeds that can reach up to 7Mbps downstream and 1.5Mbps upstream. ADSL can deliver simultaneous high-speed data and telephone service over the same line.

ADSL Lite (or G.lite)
This is a lower speed version of ADSL and provides downstream speeds of up to 1Mbps and upstream speeds of 512 kbps, at a distance of 18,000 feet from the service provider's premises. It is intended to simplify DSL installation at the user's end.

R-ADSL - Rate-Adapative Digital Subscriber Line
The R-ADSL provides the same transmission rates as ADSL, but an R-ADSL modem can dynamically adjust the speed of the connection depending on the length and quality of the line.

HDSL - Hight Bit-Rate Digital Subscriber Line
The HDSL provides a symmetric connection, that is, upstream speeds and downstream speeds are the same, and range from 1.544Mbps to 2.048Mbps at a distance of 12,000-15,000 feet. Symmetric connections are more useful in applications like videoconferencing, where data sent upstream is as heavy as data sent downstream. HDSL-II, which will provide the same transmission rates but over a single copper-pair wire, is also round the block.

IDSL - ISDN Digital Subscriber Line
The ISDN Digital Subscriber Line provides up to 144 kbps transmission speeds at a distance of 18,000 feet (can be extended with a repeater), and uses the same techniques to transfer data as ISDN lines. The advantage is that, unlike ISDN, this is an "always on" connection.

SDSL - Symmetric Digital Subscriber Line
SDSL supports symmetric (equal downstream and upstream) data transmissions up to 1.54Mbps.

VDSL - Very High Bit-rate Digital Subscriber Line
VDSL is the fastest of all xDSL flavors and provides transmission rates of 13-52Mbps downstream and 1.5-2.3Mbps upstream over a single copper-pair wire, at a distance of 1,000-4,500 feet from the service provider's premises.

VDSL2 - Very High Bit-rate Digital Subscriber Line 2
VDSL2 is faster than VDSL and provides transmission rates up to 100Mbps at longer distances.

Disadvantages of DSL

One of the major disadvantages of DSL is that it is distance-sensitive. The further your home is from your telephone company's central office (CO), the lower your bandwidth becomes. In general, the maximum distance for DSL is about 18,000 feet (3.4 miles).

Additionally, the quality of your home's wiring can affect your bandwidth. With DSL, you should use a filter to reduce unwanted noice on the telephone line, such as the one illustrated.

Lastly, DSL has a low upload speed. For most that only access the Internet to watch movies, listen to music, check email, do shopping, and similar activities, DSL is generally sufficent. However, if you do web conferencing, play online multi-player games, or stream on YouTube or Twitch, DSL would be too laggy for an enjoyable experience. For these type of activities, cable or fiber Internet connection are the better options.


2 Wire, 1 Line DSL Filter - for Removing Noise and Other Problems

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Should I Get DSL Internet?

Although DSL is a step up from dial-up Internet, DSL is one of the slower connection available in the United States. If you live in an urban area, you will likely have access to the much faster cable or fiber technologies for Internet access. With cable Internet, speed can range between 10 to 500Mbps and fiber between 50 to 1,000Mbps. These speeds are significantly much higher than DSL's 1 to 10Mbps. Additionally, the cost of a low tier cable or fiber subscription plan may cost as much as a DSL plan. And in some case, may even be less.

With the type of content and services most people access through the Internet (such as movies, music, streaming, online classroom, and web conferencing), DSL does not have the bandwidth to support them effectively, particularly if more than one of these type of content or services are being access or used in your household at the same time. The recommendation is to get DSL Internet if cable and fiber are not available in your area.


In summary, DSL can be considered if your Internet activities are light or if cable and fiber are not available in your location.

Advantages Disadvantages
 Affordable  Low speed
 Large coverage area  Distance-sensitive
 Does not affect your landline phone calls  Susceptible to electrical noise

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