broadbandbuddy.com.au
broadbandbuddy.com.au
learning centre » idsl: hybrid of isdn and dsl

IDSL: hybrid of ISDN and DSL

 

more sponsored links
If you’ve heard the term “IDSL” but still aren’t sure what it is, this article gives you the basics: IDSL background, whether you can get it, how to do so and how it affects Australian communications, and perhaps most importantly if it is really all it’s cracked up to be.

What is IDSL?

IDSL stands for “ISDN Digital Subscriber Line”, being a hybrid of “Integrated Service Digital Network” (or “ISDN”, which is a digital telephone service that provides quick data transmission over traditional copper telephone wiring), and Digital Subscriber Line (or “DSL”, which is the basis of broadband’s service). ISDN was traditionally the earliest way to send large files over the Internet, still being a dial-up service, rather than an “always on” service (which broadband is). This result of this convergence is that IDSL is of a higher speed than IDSN, but is slower than most DSL services (the most popular of these services in Australia being the “Asymmetric Digital Subscriber Line”, or “ADSL”, and its successor ADSL 2+). Whilst ISDN is similar to dial-up in its make-up, it can simultaneously provide space for both telephone and fax to function, which dial-up can’t.

IDSL largely uses the same technology as ISDN, but the signal is routed through different equipment (not via the voice switch) at the phone company’s office, instead using the same equipment as DSL, resulting in an increase in speed to 144 kilobits per second (kbit/s) and an “always on” connectivity, as with all DSL connections.

IDSL is sometimes of use as a connection if standard DSL cannot be attained – i.e. lack of availability in a certain area. Due to IDSL’s qualities deriving from traditional telephone wiring, there were calls for a long time to introduce this service in rural Australia where standard broadband could be readily enabled. Broadband’s availability has since vastly improved, however.

Pros of IDSL

  • Not limited by distance from the telecommunications exchange, as is the case with DSL
  • “Always on”

Cons of IDSL

  • Requires its own phone line, with a separate one for phones, resulting in higher costs
  • Does not reach data transfer speeds as other forms of broadband.

IDSL in Australia

Although the benefits of IDSL are clear for customers in rural areas – a reasonably quick Internet connection where ADSL cables have not been laid - it is yet to be implemented in Australia, as well as in many other countries. It is possible that, with infrastructure constantly improving and broadband range not being as much of an issue as it once was, IDSL will now not be introduced.

Having said that, whilst IDSL’s connection speed cannot match ADSL or cable broadband, the fact remains that its signal can currently travel much further, meaning that it remains an option for many unable to receive ADSL, cable and wireless and afford the sky-high prices of satellite. Perhaps due to fears from the marketers of other broadband services though, this mid-range option remains largely unattainable. With the growth in wireless Internet service, including 3G networks across much of the population, it is unlikely that IDSL will be seen as a true solution anytime soon.

IDSL is related to both standard DSL broadband and high-powered ISDN dial-up, so what are its benefits and is it a long-term solution for rural Australians?
Explains what IDSL is: who it benefits and how it works. Also discusses whether IDSL is a viable alternative to broadband for rural Internet users.