Naked ADSL (or Naked DSL) is a relatively new type of broadband service. Like ADSL2+ broadband Internet, Naked ADSL services are delivered over the copper lines normally used to deliver telephone calls. However, whereas ADSL2+ broadband is tacked on top of an existing phone service, Naked DSL services can be delivered over a "vacant copper pair" — a line that doesn't have a phone service already attached. This means you can have a broadband connection without paying for a landline telephone service.
Naked ADSL benefits
Unless they have family and friends overseas, many people don't use their fixed line telephone at home very often. However, even if you don't make many calls you are still paying a rental fee on the telephone line, often as a base monthly charge included with other features like call waiting, forwarding or voicemail. At its cheapest, you're looking at $20.95 per month on Telstra's HomeLine Budget plan, and that's only if you use BigPond as your Internet service provider. If you use a different ISP (such as iiNet), Telstra will charge you $27.95 as the minimum line rental.
Naked ADSL means you no longer have to pay line rental, as the Internet service can exist on a telephone line that doesn't have a phone service attached. The line rental fee isn't completely gone: ISPs are still charged by Telstra for using the copper line to your house, and they often pass this cost onto consumers within the price of the Naked ADSL plan. However, even taking this into account, Naked ADSL often works out cheaper than a traditional broadband plan with a typical Telstra phone line rental fee.
If you still want to make telephone calls from a home phone, many Naked ADSL ISPs also offer a voice over Internet protocol (VoIP) service. VoIP calls are much cheaper than regular landline calls — especially if you are calling overseas — and you can even use your existing telephone by connecting to your router through a small adapter. Many ISPs offer a VoIP account for a small fee (or for free) with a Naked ADSL service. You can also use a third-party, software-based Internet telephony service, such as Skype.
Naked ADSL downsides
There are a few technical disadvantages to Naked ADSL. For instance, you can't make telephone calls without power. As well as disconnecting you from the Internet, power loss means your VoIP connection will cease to function, which means you won't be able to make 000 emergency calls. This often isn't seen as a major drawback these days because most people own mobile phones. In addition, many people tend to have cordless phones that rely on a powered base station anyway, and so can't be used in the event of a blackout. Ensure that you have alternate means of communication in such a situation before considering a Naked ADSL service.
Because Naked ADSL uses a phone line without a dial tone, you can't use a regular fax machine (which needs a dial tone). Additionally, faxes cannot be sent over VoIP reliably due to data compression. Some VoIP providers, such as Engin, have trialled a fax service over VoIP, but this has proved to be unreliable. If your business still relies on faxes, and you also want to make the switch to Naked ADSL and VoIP, then you can look into a Web-based fax service (such as Utbox) that sends faxes for you and also allows you to receive them via e-mail.