Your ADSL2+ speeds depend on a number of factors. Some are outside of your control - such as the length and quality of the copper wire from your place to the local exchange. Others are within your control, such as:
- The quality of the cabling within your premises.
For best performance, we recommend installation of a Central Splitter.
- Your ADSL 'line profile'.
These allow you to adjust your ADSL signal to achieve the best performance for your specific circumstances.
- The capabilities of your ADSL modem or router.
All routers sold by Internode support the full range of ADSL2+ protocols, including Annex M, and are IPv6 capable.
How fast can it be?
The blue and green areas on the graph show theoretical maximum speeds for Easy Broadband ADSL2+. This shows how distance affects speeds, as well as differences between ADSL1 and ADSL2+.
|Figure 1: Graph showing the maximum speeds in relation to distance of ADSL1 and ADSL2+|
Factors that may affect performance
The speeds shown on the graph are theoretical maximum speeds for various ADSL protocols on good copper lines. This means no bad joints, faulty insulation, or 'interferers' like bridge taps or loading coils. Actual speeds may vary substantially from these theoretical results, based on:
- The 'line profile' applied to your service.
- The length of copper wire from your premises to the exchange - this is always higher than the distance 'as the crow flies'.
- The number and type of digital services used by other customers over copper pairs within the same cable sheath.
- The configuration and quality of the copper wire between the exchange and your premises.
- Electrical interference from outside sources (such as electric motors).
- The configuration of the copper wiring within your premises (that is, use a central splitter for optimal performance).
- Your computer's software configuration and applications (in particular, how they use the uplink back to the exchange).
- Your ADSL hardware.
- The capacity of, load on, and access data rate of the destination host computer that you are accessing.
The most effective way to improve ADSL2+ performance is to have a central splitter installed by a licensed cabler.
So how does ADSL2+ perform in the real world?
You don't live in a laboratory, so the factors above will reduce your performance from the ideal shown in the graph.
In December 2006, we took a sample of 7,305 ADSL2+ services. Each service was connected to our own infrastructure and using the ADSL2+ protocol (G992.5 Annex A ADSL2+ over POTS).
We found the following distribution of download synch speeds:
Over 63% of these customers achieved 10 Mbps download sync or better.
How does Annex M perform in the real world?
Annex M is available in selected areas and increases the potential maximum upload speed from 1 Mbps to 2.5 Mbps. The factors that affect standard ADSL2+ performance also apply to Annex M - particularly distance and premises cabling.
Again, the 'real world' data is impressive. During December 2006 we took a sample of 401 ADSL2+ services. Each service was connected to our own infrastructure and using the ADSL2+ Annex M protocol (G992.5 Annex M ADSL2+ over POTS).
We found the following distribution of upload synch speeds:
Over 53% of these customers achieved 1.8 Mbps upload sync or better.