Switch-based call verification system (SCVS)

  This system is simple but effective -- add software to the telephone switches to enforce accurate caller ID information.  Spoofed caller ID information would result in the call not going through.   Illegal robocallers would be unable to hide behind spoofed caller ID as they do now, and I think relatively few robocallers would bother to begin with if they KNEW they were going to be rapidly caught and shut down.  Techniques are discussed to reduce the impact and implementation costs while maintaining effectiveness.