DSL, VDSL and vectoring

In short: DSL carries data over the old copper telephone lines. VDSL is the faster variant for shorter runs, vectoring reduces interference between neighbouring lines.

In more detail: The longer the copper line, the greater the attenuation and the slower the connection. That is why fibre moves closer to households in street cabinets.

In Depth

• ADSL: Up to about 16 Mbit/s (ADSL2+), asymmetric (more download than upload), distance to the exchange up to around 5 km.
• VDSL2: Up to 100 Mbit/s, on a short line up to the street cabinet. Uses higher frequencies that attenuate quickly with length.
• Vectoring: Measures crosstalk between the wires of a cable and sends counter-signals. Delivers up to 100 Mbit/s more reliably, but requires one operator to control all lines of a bundle.
• Super vectoring: Up to 250 Mbit/s, G.fast on very short runs up to about 1 Gbit/s.
• The modem: The router reports sync rate (line speed), attenuation and noise margin. See SNR and decibel.
• Alternative: Fibre to the home reaches a multiple.

See also: cable internet (DOCSIS)