This is just one of 8 or 9 numbers from (347) area code that calls my business at all hours of the day and night.  They forward to my cell phone at home.  I wake up with 3-10 voicemails every morning that are all exactly 3 minutes long, of complete silence.  I have all those numbers blocked, yet they continue to create more numbers to get through.  I have added our business numbers to the do-not-call list, but that is not stopping this.