[GelflingEssence]

Originally Posted by CamaroSS50

Actually it is the government, the FCC that has a call completion rule that prevents Telco's from blocking.

The FCC has given the OK for Telco's to block Robocalls without being fined, etc.

http://transition.fcc.gov/Daily_Rele...C-347787A1.pdf

This still relies on the integrity of Caller ID information. With SIP anyone with an internet connection can establish a phone call and set their CID info to be anything they want.