Protection at subs premises has been practically non-existent here for a good many years. Both the original BT master jack (introduced in the early 1980s) and the current NTE5 network interface incorporate a spark gap tip-to-ring, but that's it -- No series components, nothing to ground.

Here's a copy of an old Post Office training booklet which shows how it used to be done:

Protective devices used in telephone & telegraph lines (PDF, approx. 1.3MB)