That's not crazy, it is the "VOIP phone number" which is used for computer-to-computer calls.
These call originators don't have a phone number until they want to call PSTN numbers. Services like Magic Jack, Vonage, Google Voice, Skype, provide phone numbers when the customer pays for it.
VOIP= Voice Over Internet Protocol
PSTN = Public Switched Telephone Network
Got this call on Labor Day, 5 September 2016, so they are still going. Picked it up and whoever it was hung up. Won's waste my money returning their call to find out more. Does anyone know what CIAVF stands for or means? (Thanks, William, for your definitions of VOIP= Voice Over Internet Protocol and PSTN = Public Switched Telephone Network.)
Caller ID: CIAVF Machine answered and male began talking, saying, "This is Mark Morrison, how are you today?" Poor Mark hung up after there was no response.
Called 3:04pm. I was on the phone at the time, and for some reason this call didn't/doesn't show up in my Caller ID history.
I didn't take the call, and a VM was left: a pre-recorded/digital male voice said, "This is Ray Kruset (sp?) How are you today? Are you there?" then disconnected.
No Caller ID info to share, but this is definitely another unsolicited/nuisance roboscam call.