They keep trying to get through to us, but it never works. My guess is they're using a robo-dialer, and said dialer does not like the 'Out of Service (SIT) tone sequence our Asterisk system sends (same thing the old 'Telezapper' did) when it first answers. The dialer's probably hanging up on its own.
Some Googling turned up a possible lead on these slime-suckers at this link.
954-417-8715, called three times. Yesterday twice, today once. Comcast. says to block them.
Called ID reads "Tech Support"
When I answer phone I get dead silence.I don't think that it is a sound of a robot call. It is dead silence. When I call the number I get the same dead silence.
I reported it to Comcast but they did not seem to be helpful. They suggested that I block the number.