Not later than June 30, 2021, each intermediate provider shall fully implement the STIR/SHAKEN authentication framework in its internet Protocol networks. To fulfill this obligation, an intermediate provider shall:

(a) Pass unaltered to the subsequent intermediate provider or voice service provider in the call path any authenticated caller identification information it receives with a SIP call, subject to the following exceptions under which it may remove the authenticated caller identification information:

(1) Where necessary for technical reasons to complete the call; or

(2) Where the intermediate provider reasonably believes the caller identification authentication information presents an imminent threat to its network security; and

(b) Authenticate caller identification information for all calls it receives for which the caller identification information has not been authenticated and which it will exchange with another provider as a SIP call, except that the intermediate provider is excused from such duty to authenticate if it:

(1) Cooperatively participates with the industry traceback consortium; and

(2) Responds fully and in a timely manner to all traceback requests it receives from the Commission, law enforcement, and the industry traceback consortium regarding calls for which it acts as an intermediate provider.

[85 FR 73395, Nov. 17, 2020]