ADSL advantages and disadvantages
ADSL offers a number of advantages over 'dialup' Internet access:
- It is always-on - the connection is always available without needing to wait for ages to 'dial up'. It also doesn't 'drop out'. 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?
- 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.
- Agile data services or ISDN are great alternatives in many situations where ADSL can not be delivered.
- 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 SDSL 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.