A little bit about ADSL
ADSL stands for Asymmetric Digital Subscriber Line.
There have been several evolutions of the technology since its inception collimating in the current version ADSL 2+. This has a theoretical max speed of 25Mb down. Ordinary copper phone lines are used which keeps installation costs down.
What affects ADSL speed?
Basically, the longer the line the lower the speed. There are other factors which affect the internet speed.
- long lines tend to have more joints and every joint has a risk of getting damp or week causing interference.
- There is a higher chance of branches scraping the lines.
- Underground cables may get broken and water gets in.
We (Megganet) have found that speed may also be affected by internal phone wiring (removing the bell wire), incorrectly connected phones, poorly filtered lines etc.
Making sure that if internal cabling was used, it was pure copper instead of telephone extension lead which contained a lot of aluminium. We also insisted the modem goes on the master socket.
The quality of modem can be a big factor here with certain big brand expensive modems fairing up to 40% lower speed than the Netgear DG834 and the 3Com we used.
When we started Megganet in 2003, we purchased about 40 modems and routers and extensively tested every single one of them to find out which was the very best in each situation. We settled on the Netgear DG834 for long lines. We also experimented with basic and active filters and we developed a powered filter – it wasn’t much help. Removing the de emphasis components in the modem helped but it did mean that the routers needed to be frequently re started. Routers used by our competitors simply could not handle the range so we wound up with the ‘difficult to install’ clients.
Real baptism of fire but entering the marked at the hard end meant we had to try harder, learn more and fight harder to get reliable ADSL circuits installed.
Originally, ADSL had 3 speeds, 500kb, 1Mb and a mighty 2Mb. 2GB, goodness me, you would never need to use all that!
That was 2003.