; and (2) retain records relating to each call transmitted over the covered VoIP service of such provider that are sufficient to trace such call back to the source of such call. (b) Report to Congress Not later than 18 months after the date of the enactment of this Act, the Commission shall submit to Congress a report on the results of the study conducted under subsection (a). (c) Covered VoIP service defined In this section, the term covered VoIP service means a service that— (1) is an interconnected VoIP service (as defined in section 3 of the Communications Act of 1934 ( 47 U.S.C. 153 )); or (2) would be an interconnected VoIP service (as so defined) except that the service permits users to terminate calls to the public switched telephone network but does not permit users to receive calls that originate on the public switched telephone network.