What is ADSL?

ADSL stands for 'Asymmetric Digital Subscriber Line'. It provides high speed, always-on access to the Internet from your home or business telephone line,.

By sending digital signals over the telephone line, it provides broadband Internet access without interrupting your normal (and concurrent) use of the telephone line for placing and receiving phone calls.

It provides an effective way to provide Internet access in a variety of situations, without the complications of configuring and operating a modem. It has a number of technical advantages compared to accessing the Internet via a dialup modem or other means.

The 'Asymmetric' part of these services is related to their data transfer speed, which is slower on the 'upload' (to the Internet) direction than it is on the download (from the Internet) direction.

This is similar to a 56k modem, which is only 'fast' in the download direction, and slower uploading.

Most other commonly available data services (such as Telstra leased lines, ISDN and Agile broadband services) are Symmetric - meaning that the upload and download speeds are the same.

(Internode has a symmetric option for DSL as well, which offers a 512 kilobit per second transfer rate in both the upload and download directions - it is actually an ADSL service where the upload and download speeds are the same..!)

How fast is ADSL?

You have a choice of access speeds with ADSL:

256/64 kbps

Which means that your peak download speed (from the Internet) is 256 kilobits per second, and your peak upload speed (back to the Internet) is 64 kilobits per second.

This speed is the entry level of ADSL broadband, and is suitable for web browsing, Internet banking and email. However Internode do not recommend - nor support - using NodePhone or other voice-over-IP applications at this speed.

 

512/128 kbps

Which means that your peak download speed is 512 kilobits per second, and your peak upload speed is 128 kilobits per second.

This is a popular choice for budget broadband, with twice the speed of the 256/64 kbps at only a small increase in price. NodePhone and other voice over IP applications can be used on this speed, however customers should take care not to generate too much traffic whilst using Voice over IP, or conversation quality may be impeded.

1500/256 kbps

Which means that your peak download speed is 1500 kilobits per second (or 1.5 Megabits per second), and your peak upload speed is 256 kilobits per second.

This is another popular choice, with good performance for most Internet applications and widespread availability across Australia - though if you can get Extreme ADSL2+, then get it!

512/512 kbps

Which means that your peak download speed and your peak upload speed are both 512 kilobits per second. Note that due to the way TCP/IP works, you will not be able to attain the peak speed in both directions simultaneously.

This speed is only recommended for customers in need of higher upload speeds who do not have access to Internode Extreme ADSL2+.

Up to 8192/384 kbps (ADSL Plus)

Which means that your peak download speed may be up to 8192 kilobits per second (depending on the length and quality of your telephone line), and your peak upload speed is 384 kilobits per second.

This speed is recommended for heavy and enthusiast users who do not currently have access to Internode Extreme ADSL2+. This speed will support high quality Voice over IP, as well as high quality video streaming and other interactive Internet content.

Extreme ADSL2+

Extreme ADSL2+ is Internode's premier ADSL product. Extreme ADSL2+ is provided over our own infrastructure in selected telephone exchanges.

Because it is provided over our own infrastructure, it enables us to provide superior value, speed and service. For more information click here.

Naked ADSL2+

Naked ADSL2+ is Internode's first 'Naked' ADSL product. Naked ADSL2+ delivers the latest high speed broadband, without the need for you to maintain a traditional telephone service. This product is available in most metropolitan telephone exchanges across Australia.

If you've already made the move to the cost-savings of NodePhone voice-over-IP - and/or the convenience of mobile phone communications - you could save real money on phone line rental. Read more about 'going naked' here.

Compare the above speeds to a conventional modem, which typically can download at around 45 kilobits per second and upload at around 31 kilobits per second, and you can see the dramatic speed difference available with ADSL - up to 30 times faster than a modem, with no dialup delays when connecting, and no blocking of your normal telephone service.

This speed difference is truly revolutionary - it changes your perception and experience of the Internet in dramatic ways.

What advantages does ADSL offer?

ADSL offers a number of advantages over 'dialup' Internet access:

 

• It is very quick to connect - the connection establishes very fast, without needing to wait for ages to 'dial up'. It is 'just there' - when you need it, instantly.
• It is dramatically faster than a dial modem or ISDN connection - up to 30-50 times faster, in fact! This makes an enormous difference to the effectiveness of your Internet experience
• ADSL seamlessly 'shares' a phone line along with normal 'voice' services. Your phone is not engaged when you are using the Internet - in fact you can freely use the phone at the same time as you access the Internet! No more busy signals for people trying to contact you while you surf.
• No second phone line needed. You can easily offset the costs of ADSL by $30 per month or more - this is the amount you might have otherwise spent on a second phone line and on local calls to access the Internet with a modem, without interrupting the use of your primary telephone service.
• You can save time and frustration by never having to wait for a modem to connect, or suffering connection dropouts, in addition to the hugely increased download speeds available
• It is far more cost effective than any previous alternatives for providing broadband connections to most home or office locations. Most other technologies providing access at more than 256 kilobits per second to residential and small business environments are more expensive than ADSL

What are the limitations of ADSL?

Nothing is perfect, and ADSL is no exception.

There are a number of technical limitations and issues to be aware of when contemplating an ADSL connection to the Internet:

 

ADSL is not available on all phone services

Some design aspects of the Telstra copper line network mean that some locations cannot support an ADSL service - even if your exchange is nominally 'ADSL enabled'. These Telstra network limitations are beyond our control.

Business customers can choose from a range of Internode data solutions - such as SHDSL and Ethernet - if they need more capacity (or are unable to obtain) Internode ADSL.

ADSL is not a guaranteed bandwidth service

Unlike conventional leased line services, the achieved performance of the ADSL network is not guaranteed.

Telstra's copper line network architecture, and the manner in which ADSL data is moved around the city, mean that network congestion is possible in your line at some times. The speeds quoted for ADSL services are theoretical maximum rates.

Performance of the network may vary by time of day or may decrease over time due to increased network interference in the Telstra copper line network.

ADSL is only fast in one direction

The asymmetric transfer rates provided by ADSL are designed to optimise the speed of Internet downloads.

As a consequence, the upload speed on ADSL is far slower.

This means that ADSL is often unsuitable for situations where you intend to upload (or serve) large quantities of data from your location back out into the Internet.

However, we now have our SHDSL service offering available for situations where you wish to have symmetric throughput, at a slightly higher cost.

ADSL is less reliable than dedicated broadband links

Because ADSL runs over the copper voice telephone network, ADSL achieves a lower reliability level than a business oriented leased line connection.

• If an ADSL connection fails, it may take some time to restore.
• Telstra reserve the option to 'modernise' their network at any time, which may result in an ADSL service becoming permanently unavailable on your line.
• Telstra will not guarantee the long term provision of ADSL and may withdraw the service permanently from being available over the copper line network in some or all locations.

Alternatives to ADSL

Internode can offer you a variety of other broadband options where the variability in speed, slower upload rates, lower reliability, and no long term guarantees of ADSL is not acceptable - this is especially important in business scenarios, where you may need to rely upon your Internet link to stay in business.

Internode data services offer symmetric, broadband data links from 256k up to 1000 megabits per second, with service level agreements and proactive 24 hour monitoring and restoration of service failures.

We provide these services with a variety of technologies, including broadband radio, ethernet, fibre optic cables, and dedicated (non-voice) copper lines.

Please contact our Sales Team for further information on these products.