; and (B) an assessment of the efficacy of the STIR/SHAKEN authentication framework, as being implemented under this section, in addressing all aspects of call authentication. (4) Review and revision or replacement Not later than 3 years after the date of enactment of this Act, and every 3 years thereafter, the Federal Communications Commission, after public notice and an opportunity for comment, shall— (A) assess the efficacy of the call authentication framework implemented under this section; (B) based on the assessment under subparagraph (A), revise or replace the call authentication framework under this section if the Commission determines it is in the public interest to do so; and (C) submit to the Committee on Commerce, Science, and Transportation of the Senate and the Committee on Energy and Commerce of the House of Representatives a report on the findings of the assessment under subparagraph (A) and on any actions to revise or replace the call authentication framework under subparagraph (B). (5) Extension of implementation deadline The Federal Communications Commission may extend any deadline for the implementation of a call authentication framework required under this section by 12 months or such further amount of time as the Commission determines necessary if the Commission determines that purchasing or upgrading equipment to support call authentication would constitute a substantial hardship for a provider or category of providers. (c) Safe harbor and other regulations (1) In general The Federal Communications Commission shall promulgate rules— (A) establishing when a provider of voice service may block a voice call based, in whole or in part, on information provided by the call authentication framework under subsection (b)