The caller left no voice message.

Caller ID came up "Out of Area".  No message.  Google lookup lists it as an unsolicited call from Comcast (I have ATT U-Verse).  Blocked caller #597 (two Panasonics +  20 ATT IDs), idiot call #1245 (not including obvious mis-dials) since 5/2/13.  Caller ID "1" (100-000-0000) has called 70 times, including 12 in one day, 6 on another.  I also had to block my own scammed number as four times the caller ID indicated that I received a call from IT!

I have kept all of these numbers on a spreadsheet with dates and number of calls.  Since both blocking systems are full, I have been recycling the older numbers that only called once or twice.

Rang once no message. I suspect a spoofed cID

IMHO:
Spoofing caller ID (using internet phone system) and calling people on state and federal DNC lists under the guise of a survey and free product with hidden charges or telemarketing, should be a crime as per the Computer Fraud and Abuse Act (CFAA).

Search shows the number as Comcast 301 Tower Rd, Naples, FL 34113. Comcast in Naples FL.
I don't have their cable service and there is no reason to call me other than illegal telemarketing.

Called while I was on a call so I didn't answer. Caller ID on call waiting said Comcast. Within seconds of hanging up on my personal call, got a call with caller ID Out of Area. It's been blocked. Called the Comcast number back and message said " we're sorry. We cannot complete your call as dialed. Please check the number and try again."  Strange if this were really Comcast. Comcast does not call out of the blue, and I'm a Comcast customer.