This same group calls constantly. The call try's to make you think there is a bad connection by cutting out. Then a recording and sometimes a real person comes on the line and asks, "Can you hear me? It's my opinion that they are recording your voice and trying to get you to say "yes". Then they can use your recorded voice saying "yes" to their question of "Would you like us to send you a free back brace, knee brace, or whatever and then bill Medicare for it. Oh, and along the way they're collecting your personal info. Never say the word "Yes" on one of these calls and never give any personal information. Better yet, don't even answer calls from numbers you don't recognize!
Came up as a California number, but most likely is a Telemarketing center from another country and the reason some of your caller IDs are showing "invalid number." I just don't answer these calls. I have stored everyone's number that I personally know so that their name comes up when they call. All others get ignored, deleted and/or blocked.