How Does Broadband Internet Work?

  • Broadband internet - what it is and how you can get it
  • ADSL, ADSL2+, Naked DSL, cable and mobile broadband
  • Finding the best broadband plan for you

An ADSL, ADSL2+ or Naked DSL broadband connection uses the existing copper wire for your home telephone service to transmit data to your broadband modem. Your modem connects to the internet via the copper line and translates the data for your computer to browse the internet. An ADSL broadband service is always on so you no longer need to connect each time you want to browse the internet.

The most popular way of connecting to the internet in Australia is over the copper landline on one of these services. The alternatives are mobile broadband, which is over the mobile network, cable broadband or satellite broadband. We'll focus on ADSL technologies in this article but we also have an article about cable broadband and mobile broadband.

Find the fastest ADSL2+ plans

You can also call us on 1300 106 571 for more information on broadband plans in your area.


ADSL (Asymmetric Digital Subscriber Line) is asymmetric as it allows data to travel to your computer (downloads) as well as transmitting data back to the internet (uploads.) Upload and download speeds are not symmetrical and you will always receive much fast download speeds than upload speeds. For example on a 512kbps ADSL broadband plan you will receive up to 512kbps download speed but only 128 upload speed.

The broadband signal utilises frequencies not used by a voice telephone call and allows consumers to be on the phone at the same time as being connect to the internet. A splitter or line filter separates the signal to prevent interference from the broadband signal from disturbing voice calls. A dial up internet connection does not allow for this.

In order to receive and ADSL broadband connection, ADSL codes must be installed on your phone line at the telephone exchange. A technician must install the codes and this is what your ADSL setup cost pays for when you sign up to an ADSL broadband plan.

An ADSL signal will deteriorate the longer it has to travel over a copper line and is generally only effective within 5 kilometres from the telephone exchange. After this distance the signal may be too weak to be worthwhile as speeds will be too slow to count as a broadband connection.

In the near future, the National Broadband Network proposes to bypass use fibre optic cables instead of copper wire to allow super fat broadband connections for Australian Homes and businesses. 


ADSL2+ is similar to ADSL broadband connections but they offer theoretical maximum speeds up to 24,000kbps. Your internet provider needs to install ADSL2+ infrastructure at your telephone exchange before you will be able to apply for and ADSL2+ broadband service. Just as with ADSL, the actual speeds you receive will depend on your distance from the telephone exchange.

As a result, not all areas are eligible for an ADSL2+ service as broadband internet providers are still installing ADSL2+ infrastructure across the country. The roll out so far is mainly in larger metropolitan areas like Melbourne where the uptake of an ADSL2+ service makes the initial financial outlay by your broadband provider a worthwhile investment.

While ADSL2+ is currently the fastest broadband available over the existing copper line, the National Broadband Network promises to install fibre optic wiring into Australian homes and businesses that will offer super fast broadband speeds up to 100Mbps.

Naked DSL

Naked DSL is an ADSL2+ broadband connection that doesn’t require an active telephone service. Naked DSL also runs along the copper phone line onto your house but because your internet provider is using its own infrastructure (rather than Telstra’s,) you will not need to pay for a home phone line rental. You will need to have ADSL2+ infrastructure installed at your telephone exchange to be eligible for a Naked DSL service.

 A Naked broadband connection will however, does require an active phone service before you sign up. Once the Naked broadband is connected, the home pone component of the service can be switched off and you will no longer need to pay for the service.

You can browse , ADSL2+, ADSL and Naked DSL from the major Australian providers at Compare Broadband to find the best deal to meet your needs.