The FCC has legislation under construction, with the help of the carriers and providers, to provide number validation by the end of this year I think. Then who knows how long it will take to roll out. My *basic" understanding of the planned process (for SIP, I believe) is that when a call is set up to go out a transmission key will be created to validate the sender's number, and then there will be some kind of "clearig house" that gets that key, verifies the sender that is setting up the call is authorized to send out that number, and then sends back either some kind of response key or allow/deny type of response. I'm not sure if I got that from Sans NewsBytes, or one of the publications I never should have asked for because they incessantly spam me, warning PBX owners and local carriers the new rules are coming soon. The intent is to make it next to impossible to spoof numbers.
Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA