Reply comments on caller ID authentication progress

A few organizations have filed comments on the progress of caller ID authentication implementation, as required by the TRACED Act. Here’s a summary.

The TRACED Act requires the FCC to report by the end of the year its analysis of the extent to which voice service providers have implemented STIR/SHAKEN in their IP networks and non-IP caller authentication in their non-IP networks. This request for comments and reply comments was issued on October 1, 2020 with WC Docket 20-323.

The FCC received nine comments and two reply comments.

Alliance for Telecommunications Industry Solutions (ATIS)

  • ATIS has received a significant number of contributions from members proposing mechanisms that could support non-IP authentication, including:
    • Out-of-Band SHAKEN, which is defined to be compatible with classic STIR/SHAKEN using the same governance authority, STI certificates, and PASSporT specifications
    • TDM-based, which proposes the use of existing ISUP parameters.

AT&T Services

  • They’re using STIR/SHAKEN on VoLTE wireless and consumer VoIP services.
  • They’re expanding this to business VoIP service.
  • They’re expanding bandwidth on their network to support transmission of STIR/SHAKEN information in SIP.
  • They think it’s premature to assess the effectiveness of STIR/SHAKEN. Although some large carriers are using it, deployment is not sufficiently widespread.


  • Comcast signs all calls originating from residential and small- and medium-sized business voice customers.
  • They’re receiving signed calls—about 18% of inbound calls in September 2020; 31% of calls to business customers.
Reply comments on caller ID authentication progress

Cox Communications

  • All residential customers are served by the STIR/SHAKEN enabled network.
  • Have plans to improve call blocking based on STIR/SHAKEN results combined with data analytics.
  • Expect to have the majority of business customers served by STIR/SHAKEN by end of November 2020.


  • Encourages the FCC to closely monitor progress toward permitting all service providers to participate in STIR/SHAKEN in light of the indefinite extension granted to service providers that are unable to obtain a certificate.
  • INCOMPAS has championed certificate delegation and encourages the Commission to reconsider its decision to require standards for certificate delegation.
  • Concerned about the ability of foreign service providers using NANP numbers to certify that they’re using a reasonable robocall mitigation program.


  • Service providers should publicly post their contact information to arrange STIR/SHAKEN interop testing.
  • Many voice providers cannot register as a Service Provider because they do not access numbering resources directly. This creates two problems:
    1. The very parties that may be sending unlawful robocalls are not required to attest to their calls. This undermines call authentication.
    2. Good actors originating calls are unable to play their part.
  • The FCC should encourage a system whereby non-carrier voice service providers and enterprise end users could sign their own calls.


  • Lumen is signing all IP-originated calls and transiting signed calls to providers that can receive them.
  • Equipment availability and software updates could delay Lumen’s implementation timeline.

NTCA – The Rural Broadband Association

  • The FCC report to Congress should cover progress and barriers that remain.
  • The lack of end-to-end IP interconnection is a barrier to efficient deployment of STIR/SHAKEN.
  • Rural customers face a “reverse rural call completion issue.” Their calls will be considered suspicious because of the lack of end-to-end IP interconnection.
  • Out-of-Band signaling holds significant promise.
  • The Commission should make clear to Congress that completion of the OOB standard is necessary to ensure that consumers nationwide can access caller ID authentication.


  • T-Mobile exchanges STIR/SHAKEN calls with 14 service providers.
  • Call blocking and labeling is accomplished using a combination of STIR/SHAKEN authentication and reasonable analytics.


  • Replied to NTCA comments about how the need to exchange voice traffic in IP is a barrier to ubiquitous deployment of STIR/SHAKEN.
  • USTelecom acknowledges the importance of this issue but urged the FCC to focus on positive momentum in its report to Congress.
  • Difficulties faced by smaller providers have been addressed with the two-year extension.
  • Work continues in the ATIS Non-IP Call Authentication Task Force.


  • Verizon uses STIR/SHAKEN on all of their wireless traffic and bilaterally exchange STIR/SHAKEN traffic with 14 other service providers.
  • Verizon has begun to sign some wireline traffic for some enterprise customers.
  • Verizon is expanding the scope of use cases that can be handled and introducing concepts beyond the initial baseline.

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We offer STIR/SHAKEN and robocall prevention solutions in our ClearIP and NexOSS software platforms. Contact us today to learn more about these solutions.

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