On Mon, Aug 1, 2016, 10:58 Steve Petrie,

snip

I do realize that the DSL modem provides a dial up "line" in parallel
with the high-bandwidth DSL link.

However, there is still a difference between: 1. a telephone link over a
twisted pair of physical copper wires, and 2. an emulation of a
telephone link, over a DSL modem.

The DSL modem does not provide a dial up "line" in parallel with the DSL link. DSL operates over the same wires as the traditional phone service. One does need a small filter to prevent the DSL signals from interfering with the use of the telephone link.