Automatic call blocking is now the rule of the land thanks to your very own United States federal government — that means you should be getting fewer robocalls and cold dials from spoofed (faked) numbers. It also means the roll-out of a two-part authentication system between the network sending and the network receiving named SHAKEN/STIR. This very system has just been deployed for calls between the AT&T and T-Mobile networks.
The carriers jointly announced SHAKEN/STIR (or STIR/SHAKEN) deployment this morning.
The system requires the sending network to authenticate the number of the caller and the physical location of where it's coming from — to make sure either detail has not been faked — and then send a certificate along with the call to the receiving network. That network will then verify the certificate and store the certification in a repository, then pass the call to the intended recipient along with an indication of whether it comes from a suspicious origin.
Other phone companies will have to work with each other to make sure that SHAKEN/STIR is deployed in a timely manner as required by the FCC. In the meantime, carriers are offering call blocking on their own to consumers.