I finally was able to contact our ISP about our personal Internet connection. It turns out that the local telco is locally upgrading its capabilities so that the “other” pair of wires that comes into the house will be usable.
In case you’ve never bothered to look, there are two pairs of wires in Plain Old Telephone Service. Phones only use one pair, and DSL has used the same pair by making use of such high frequencies that they don’t interfere with telephones. At least, they mostly don’t interfere.
Our ISP is now going to use the other pair of wires, so the DSL signal will be carried separately from the telephone signal. I’m a bit intrigued to see how well it works. The ISP is making appointments for on-site installs, probably to make sure that all the wires involved really have four conductors. A lot of telephone wiring has only two conductors, since that’s all that anyone’s needed for phone service. Most of our phone patch cables have only one pair.