Curious CID Behavior

[caseydoug]

I have a doctor friend who blocks his outgoing CID. When he calls me, the CID normally reads "Restricted" or some such thing. Tonight he called and left a message, which forwards to email. Although the Call History in VPanel shows the call as "restricted," which is normal, the email says "Message from Anonymous," and then shows his actual telephone number. I had never noticed that before.

Can anybody explain it?

[SpaethCo]

Blocked CID information is still transmitted between carriers, it is just flagged for privacy so that carriers will not transmit the information to end-users. Enterprise voice connections get all of the data (ie, if you think you're calling a Fortune 500 company anonymously with *67, think again) and CLECs can sometimes provide the data in the SIP header on enterprise or carrier-class trunks. I suspect VOIPo's upstream carrier is transmitting this information to them, and certain elements of their infrastructure are using the CID info.

This "feature" was made semi-famous in 2008: http://news.cnet.com/8301-13554_3-9997976-33.html

(note: FlowRoute closed their infrastructure to providing the full call details on blocked calls shortly after this went public)