They figured out the flaw to SHAKEN/STIR. It was mandated for VOIP calls. So instead these scam call centers switched to the legacy SS7, that's how you are get

They figured out the flaw to SHAKEN/STIR. It was mandated for VOIP calls. So instead these scam call centers switched to the legacy SS7, that's how you are getting all these fraudulent calls. SS7 is not IP based and incompatible with SHAKEN/STIR And it'll be 400 years from now before any US telecom thinks about discontinuing SS7.