There's a very nice way to shut out all telemarketers.
See if your LOC offers Do Not Disturb service.
Do Not Disturb service, which is often *cheaper* than No Solicitation, can be set with a 24 hour/day "no-disturb" period. To ring your phone, the caller has to know a 4-digit password set by you. You can optionally allow "emergency calling" with "*", which requires the caller to state their name (and you get to hear that before deciding whether or not to allow the call to connect).
You have to make sure that you do not have voice mail or other forwarding, since it will send your call to your voice mail if you do. An answering machine is OK.
I've done this for over a year now, and the blessed silence from my landline phone has been delightful. The handful people who are authorized to call me all know the password; and it's easy enough to program it into the speed dial on most modern phones. You can also change the password at any time.
-- Mark --