Blocking calls from telemarketers at the CPE-level is a Herculean task.

I don't know how it can be done. Predictive dialers can spoof both working and non-working telephone numbers. Even then, the dialer equipment, which at one time may have listened for the SITs to determine if a number is working or not, now looks for Answer Supervision.

I recently came across a still functional TeleZapper TZ-900 that I purchased back in the 90's. I tried connecting it to the line input on my Partner ACS. I heard the familiar tones when going off-hook and when the auto attendant answers calls. Of course, it didn't make a dent in the number of telemarketers calls I receive.

Service providers (LECs & IXCs) will need to step up their game (assuming the want) to actually block Spam calls.

I Love FEATURE 00