Comment by walrus01

There is no way to fix the ability to spoof caller ID with the way SS7 is built. Not without breaking functionality to something like 85% of the installed base of PBX and phone switch equipment, most of which is anywhere from 10 to 45 years old. The legacy telco SS7 phone system needs to be burnt to the ground and rebuilt, but it never will be, because people have moved on to friend-opt-in based message platforms like whatsapp, signal, telegram, facebook messenger, and the domestic chinese equivalents (wechat etc).