Read the forum guidelines
Over the last few days I have been inundated with "You've overpaid your utility bills so press 1 if you're a sucker" robocalls. I report every one of them to Nomorobo. All the calls come in with unverified (naturally) caller-IDs. Is there some technical reason that Cox can't implement an option that blocks all calls with an unverified caller-ID? This is beyond annoying.
The problem is, MOST of these callers are spoofing the phone numbers, and changing their number on each call. Because the numbers themselves are legitimate, but they are used minimally, they aren't blocked. If it was a telemarketer, using the same number to call from, they could log it, with NOMOROBO, and block it. Even though the numbers are non working, the only way to determine that is to call the number, and find out. Again, because it's only used a couple of times, by the time Cox could determine it's a number not currently in service, they are using a different number to call from. The ONLY way this can be fixed, is for the FCC to have a database of numbers active 'in service', and ALL telephone providers to update and maintain in real time the numbers IN service. THEN all telephone providers to block telephone numbers not in the list as a valid in service number through their switch by verification of the number to the active database in real time. .
The North American Numbering Plan Administrator (NANPA) amasses a list of assigned numbers from the providers twice-a-year and submits biannual reports to the FCC as the Numbering Resource Utilization Forecasting (NRUF).
Due to the sensitivity of this report, the FCC would never release or allow anybody to access it. However, with your suggestion, I suppose Cox could send a caller's number to the "database" and receive an "in-service" or "not in-service" response.
However, as you noted, scammers are spoofing in-service numbers, so the reply from the "database" would be "in-service" and then allowed.
You cannot rely on a company or agency to police your calls. The gov't has been failing for 20 years, and Cox does not want to get into the business of deciding which calls to block. The only foolproof way is to install a call-blocker and maintain it with an Allow Only list of numbers.
I never heard of a call blocker but just found call-blocking phones on amazon.com. Time to check these out. Tonight I got a robocall at 8:15. It's getting out of hand.
Call-blocking telephones don't won't work well with onetime-use numbers.
Scammers will use a legitimate (assigned) telephone number, war-dial hundreds of people and then move on to another legitimate number. By the time you get around to blocking this legitimate number, the scammer would have already moved on to another number. You'd just be blocking a ghost.
Call-blocking telephones do work well with the numbers persistently calling you as well as "Private" and "Unknown" calls.