Line attenuation is simply the measure of how much signal is lost on your ADSL line from when it leaves the telephone exchange. The more attenuation, the lower the signal ‘strength’, and so eventually the slower your internet connection.

This is one of the main reasons that many people don’t get the advertised ‘up to’ speeds that they expect. If you live a long way away from an exchange, then it is likely that your line attenuation is very high.

There’s a really great website that allows you to input your line attenuation, and it tells you approximately how long your telephone line is. Butit also tells you the maximum speed that your line can connect at. This is a good way to see if your line could support higher speeds, if you were planning to upgrade to a higher speed service, for example.

Here are my results for a Guernsey ADSL connection. What makes it so painful, is that the line could support full ADSL2+ speeds, but it isn’t yet available on the island.

Here’s the website: http://www.kitz.co.uk/adsl/max_speed_calc.php