[2BNTV]

I installed it two weeks ago and it works great. My phone rings once and then the robo call is diverted and squashed. I haven't gotten up once to see who's calling me. I wait for the second ring. It's much better than the "do not call" registry, which stops nothing. IMHO

Find out how Nomorobo intercepts robocalls to your phone number. Nomorobo
1 is a free, third-party service that can reduce robocalls and automated telemarketing calls to your Phone home phone.
2 Nomorobo identifies incoming calls from known robocallers and hangs up the call before you answer.

Nomorobo may:
Stop calls from parties that ignore the National Do Not Call Registry.
Allow legitimate incoming automated calls, such as school closings or doctor’s appointment reminders.

Go to Stop robocalls and telemarketers with Nomorobo

The above text it there, along with instructions, on how to set it up.

This should really stop telemarketing calls that are are a PITA, for those who don't want to be bothered with nuisance calls.