If a majority of robocalls are originating on IP endpoints as the entry to the PSTN - this would appear to solve the issue at hand, SHAKEN/STIR, is an IP only p

If a majority of robocalls are originating on IP endpoints as the entry to the PSTN - this would appear to solve the issue at hand, SHAKEN/STIR, is an IP only protocol, and has not been extended to TDM originating traffic though (nor could it be really)