robo spam using Digium Asterisk

This number called our business today at 1508 hours.  Caller ID said "Dobbs Ferry NY."  We don't have customers or vendors in New York so I assumed it was yet another spammer or scam artist.  I picked up the phone but said nothing.  After a moment, the call automatically disconnected so I suspect it was yet another annoying robo-message waiting for someone to speak before starting.

This number called our business again, this time today at 1416 hours.  As before, I picked up the phone but said nothing.  After a long moment, the call disconnected.

This number called our business yet again, this time today at 1454 hours.  As before, when I don't speak, the call automatically disconnects.  I get so tired of the scam artists and the cold-calling spammers every single day, multiple times a day.

And yet again, today at 1133 hours.  They are nothing if not persistent and idiotic.  They're also apparently ignorant about the law about auto-spamming.