The term you're looking for is "demarc" or: https://en.wikipedia.org/wiki/Demarcation_point

This is the physical boundary of a network, in telecommunications. This is the junction where the service provider can point and say "that's our equipment on this side". So it helps to narrow down the troubleshooting.

Often, if you have a telephone landline, you will see your demarc take the form of a gray RJ11 box with a small self-plug in it. It would be common practice to plug a phone into that box directly, then you've eliminated the "inside wiring" in the house.