[asterisk-users] How to detect fake CallerID? (8xx?)

[Doug Lytle]

>>> I ask my SIP provider to include more headers to show the real ANI? What would that service be 
>>> called?

If it's anything like a PRI provider, I've been told they only way to get true CID, in those instances, would be to provide a 1-800 number (US) for them to call. Then you'd get correct CID, since you're paying for both legs of the call.

I do not know if this holds true for a SIP provider,

Doug