Short for Asymmetric Digital Subscriber Line, ADSL is a type of DSL connection that utilizes the frequencies on regular copper phone lines that aren’t taken up by voice calls. The advantage of this kind of connection is that it doesn’t require any special lines to be installed, so it’s less expensive and more available than other forms of broadband. With ADSL, you can get up to 24 Mbps download speed, but upload speeds are much more limited. Both speeds are affected by the condition of the wires, the distance between your home and the provider’s location and any noise or interference on the line. Living “upstream” from your Internet provider is likely going to mean you get inferior service to those who live “downstream,” hence why this connection is known as asymmetrical. Better speeds are attainable with ADSL2+, a newer generation of ADSL connection available to those living within two kilometers of an exchange.
Very-high-bitrate Digital Subscriber Line service is closer to cable Internet in speed and behavior than ADSL. It can be up to five times faster for downloads and ten times faster for uploads. Maximum upload speeds hover around 60 Mbps if you live close to the provider, and the signal is just as strong upstream as it is downstream. VDSL accomplishes this with more efficient use of phone lines achieved through a configuration that effectively shortens the distance that the signal has to travel. Shorter distances means less degradation and a more reliable connection. A higher amount of available bandwidth delivers better overall performance than ADSL can offer. However, distance and wire condition can still affect VDSL.