DSL (Digital Subscriber Lines): How does it work?

DSL is one of the most popular types of High-Speed-Broadband service available in the market today. Digital Subscriber Lines owe its popularity to faster connections speeds and ease of setup. Installing a DSL connection only requires an available phone jack together with an existing telephone service. Getting DSL services is easy as it is usually provided by your local telephone service provider.

Equipment Needed for DSL

All equipments required for a DSL connections usually comes as a package together with your new service. Setting up your new connection is easy with instruction manuals or a quick call to your DSL service support hotline. For those of us who are not that technically savvy, a technician could be scheduled to install the equipment for you.

MODEM (Modulator Demodulator)

This is an electronic device that usually comes with your internet connection. This device translates signals from the network provider to signals which your computer understands. It usually comes in the form of a box with lights on it. Status of internet connection is conveniently displayed by the lights.

Filter

Along with your modem comes a small box with two ports or holes which is labeled “Filter.” An improperly placed filter connection could lead to intermittent internet connections or worse no internet connections at all. This is usually located between the modem and the phone jack and connected by wires. Labels are located above the ports for proper placement of phone DSL line. The filter serves to separate high frequency (for DSL) and low frequency (for phones) signals.

Phone jack

This is the port where you usually connect your phone cables going to your phones in the home. Telephone service providers also provide broadband services and signals for DSL connections are channeled through the same wires as your phone.

Ethernet Card

This is a device located at the back of your PC; it has a port which shape is similar to the ends of the Ethernet cable. This device accepts the translated signals from your modem into your PC. This is different from your dial-up modem. The port from the Ethernet card is significantly bigger than the dial-up modem.

Cables

There are three cables which usually come with the DSL package. Wires included in a basic DSL package are the power cables, Ethernet cables and DSL cable. These cables can be distinguished by their colors sizes. Power cable for the modem comes in standard black and has a plug at the other end. DSL cables is gray and thin compared to the Ethernet cables. Ethernet cables which are used to connect the PC to the modem come in gray, blue or yellow.

How does a DSL connection work?

A DSLAM or Digital Service Line Access Multiplexer which is located at the central office gathers digital signals from DSL connections. This serves to connect DSL services to the internet provider’s servers which in turn connect to other servers. This interconnection of servers and providers make up the World Wide Web or the information highway.

Communication to the internet is done through your network provider which assigns you a specific address. This is similar to your home address where people can send information to and from with the use of their network servers. Network servers function much like local postal services which direct traffic through different locations.

Below is a simple step by step description on how you connect to the internet using DSL connection.

1. It all begins with a simple click on your web browser (Firefox, Internet Explorer and Safari). By typing a specific location, searching or clicking a link you instruct the computer to find a specific location on the internet.
2. These signals or instructions are sent to the modem through the PC’s Ethernet card. The Ethernet cable which serves as the pathway of these signals transmits it to the modem.
3. The modem acts as a translator between the network servers and computer. The modem transforms your computers instructions to information which could be understood by the network servers.
4. These signals are transmitted to your network by use of telephone wires and cables. A DSL cable runs from your modem to your phone jacks. These phone jacks also serve as a port for your telephones. Filters are used in instances where there is only one available phone jack for both your DSL and phone. This serves to separate the analog (phone) and digital (DSL) signals.
5. Signals exit your home and run through telephone cables to the network provider’s Central Office. Imagine these telephone wires acting like a two lane information highway. On one side run analog or low frequency signals for your phone communications and the other for digital or high frequency signals for DSL.
6. These signals finally reach their destination which is your network or phone providers central office. Much like your home Filter, the central office’s Main Distribution Frame distributes these signals for Regular POTS (Plain Old Telephone Service) and DSLAM. The information you sent through your computer is channeled to the DSLAM as passed to the Network Servers.
7. Your Network Servers communicate with other Network Servers and look for the information on their own network of computers. Information gathered is then communicated back to your Network Servers and travel through similar paths back to your computer.
8. The information gathered through the internet is then displayed on your desktop.

Even looking at these simple steps makes you wonder why it takes only split seconds for information to travel to and from your computer. Your network servers maybe located miles away from your home and the location of the information you’re looking for maybe half-way around the world. Signals travel through the wires at thousands of feet per second. So the next time you power on the computer open your web browser and try to appreciate the complicated sequence of events that happen before a single letter on that website is loaded.