Network and infrastructure
Local loop unbundling
Local loop unbundling opens the incumbent's local loop to other operators, who rent the copper line and install their own equipment on it.
It is partial when the alternative operator takes only the line's high frequencies while the phone subscription stays with the incumbent; it is full when it takes the whole line. Introduced in France in the early 2000s under the regulator's supervision, it lowered the price of internet access and made the router the household's entry point.
Why it matters for fax
Full unbundling was, long before fibre, the moment many fax machines lost their analogue line without their owners noticing: the wall socket still worked, but the phone now went through the router as voice over IP.