This is akin to the BCP 38[1] problem with ISPs. I suspect few SIP-based telcos do validation of originating numbers today. STIR/SHAKEN has the potential to he

This is akin to the BCP 38[1] problem with ISPs. I suspect few SIP-based telcos do validation of originating numbers today. STIR/SHAKEN has the potential to help here, but there are still shortcomings, e.g. when originating calls with source numbers obtained from other carriers[2]. 1. https://tools.ietf.org/html/bcp38 https://tools.ietf.org/html/bcp38 2. https://support.bandwidth.com/hc/en-us/articles/360025664313-What-Is-STIR-SHAKEN-and-How-Does-It-Impact-Robocalling- https://support.bandwidth.com/hc/en-us/articles/360025664313...