Got a call from this number.  I answered it and no one was on the other end.  I called it back and it only rang once and there was no answer on the other end.  It is really a suspicious call.

215-564-6741 = caller ID = Philadelphia PA = spammer keeps calling home phone, cell phone, my mother who does not own a computer = never leaves a message, won't ID themselves (hangs up) so I am blocking and so should you!

These calls appear to be coming from Robo dialers that rely on Voice over Internet Protocol (VoIP).  Calls similar to this are pinging the cable modem and checking for the built-in telephone modem.  For a while, resetting IPv4 and IPv6 security stopped this dead in its tracks, but the spammers appear to be over-coming my protections.  Placing these numbers on the "blocked calls" list has no impact because the spammers/spoofers are using a variety of numbers.

No message left. Says Pennsylvania in the caller ID.