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NNI Task Force Introduction

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Important NNI Task Force Announcement:

TRACED ACT Signed Into Law and the U.S. Federal Communications Commission Mandates Adoption of STIR/SHAKEN Call Authentication Framework developed by the SIP Forum/ATIS NNI Task Force.

With the recent signing into law of the “Pallone-Thune Telephone Robocall Abuse Criminal Enforcement and Deterrence Act”, or the “TRACED Act” (S.151), by President Trump on December 30, 2019, there is new urgency surrounding the deployment of STIR/SHAKEN within the telecommunications industry.

In addition, on March 31, 2020, the United States Federal Communications Commission adopted new rules requiring implementation of caller ID authentication using “STIR/SHAKEN.” These rules will further the FCC’s efforts to protect consumers against malicious caller ID “spoofing,” which is often used during robocall scam campaigns to trick consumers into answering their phones.

The TRACED Act authorizes the Federal Communications Commission (FCC) to issue additional civil penalties on individuals who intentionally violate restrictions on the use of automated telephone equipment (i.e., illegal robocalls and spoofing); and directs the FCC to require voice service providers to offer call authentication technologies (i.e., STIR/SHAKEN) to consumers.

About the SIP Forum/ATIS NNI Task Force

The global communications industry is currently in the midst of an important transition from the legacy PSTN (Public Switched Telephone Network) infrastructure to a newer, more advanced SIP (Session Initiation Protocol) and IP-based infrastructure. Today, many advanced services cannot reliably work end-to-end because the interconnection between service providers often still occurs via the PSTN’s TDM-based (Time Division Multiplexing) facilities.

Although IP-based SIP interconnection between service providers is increasingly common, each agreement must be negotiated and engineered on a case-by-case basis, leading to duplication of effort. Typically, equipment, such as Session Border Controllers, is used to “normalize” the protocol at the edge of each network to ensure the interconnection will work. The overall effect is to significantly increase the operational and capital cost of SIP/IP-based interconnection. In addition, there is no commonly-agreed methodology on how to translate phone numbers for routing data for SIP-IP interconnection.

The Alliance for Telecommunications Solutions (ATIS) and the SIP Forum formed a Joint Network-to-Network Interface Task Force to fully specify an IP communications network-to-network interface between North American service providers. The Joint Task Force will enable the goal, identified in the United States National Broadband Plan, of ensuring all service interconnection between providers occur at the Internet Protocol (IP) level. By enabling ubiquitous IP-based interconnection, the Task Force supports wide-scale availability of IP-based voice services, and for laying the groundwork for ubiquitous advanced real-time communications such as high-definition voice, point-to-point video calling, and multimedia text across wireless, wireline and cable providers.

The SHAKEN Call Authentication Framework

To address unwanted and illegal Robocalls, ATIS and the SIP Forum have been working to develop standards to verify and authenticate caller identification for calls carried over an Internet Protocol (IP) network using the Session Initiation Protocol (SIP). The ATIS and SIP Forum work consists of a three-phase approach to solving the issue of caller identification, using a digital certificate scheme to “verify and authenticate caller identification for calls carried over an Internet Protocol (IP) network.”

Phase 1 (completed) consists of the development of the SHAKEN framework, based on the protocols developed by the IETF’s STIR working group (the STIR framework), and describes the operations necessary for making an authenticated telephone call using the SHAKEN framework.

Phase 2 (completed) consists of the development of a “Governance Model and Certificate Management for the Trust Anchor,” describing the way in which entities will be granted the trust necessary to vouch for call authenticity, and the organizational structures needed to manage this process. Specifically, this work introduces a governance model and defines X.509 certificate management procedures. Certificate management provides mechanisms for validation of a certificate and verification of the associated digital signature, allowing for the identification of illegitimate use of national telecommunications infrastructure.

Phase 3 consists of the development of a “Call Validation Display Framework” that will recommend how to display SHAKEN/STIR information to consumers. Phase 3 is still being developed by ATIS and the SIP Forum.

How to Join the Effort

Participation in the ATIS/SIP Forum Joint Task Force is currently open to ATIS and/or SIP Forum members.

To join the effort, you must already be an Individual “Participant” Member of the SIP Forum. This membership is completely FREE.

If you are not yet a Participant Member, please register. (Note: This link will take you to a quick and easy online form).

Once you are registered, please visit the NNI Task Group Charter page.

At the top of the charter page, you will find a link to subscribe to the NNI TF Mailing List.

SHAKEN and Other NNI Task Force Documentation

The following documents produced by the NNI Task Force are available for download:

  1. Joint ATIS/SIP Forum Standard – Signature-Based Handling of Asserted Information Using Tokens (SHAKEN): Governance Model and Certificate Management.This is the PDF version of the ratified standard. This specification expands the SHAKEN framework, introducing a governance model and defining X.509 certificate management procedures. Certificate management provides mechanisms for validation of a certificate and verification of the associated digital signature, allowing for the identification of illegitimate use of national telecommunications infrastructure. Published on July 11, 2017.
  2. Signature-based Handling of Asserted information using toKENs (SHAKEN)
    This is the PDF version of the ratified NNI Task Force “SHAKEN” document. Signature-based Handling of Asserted information using toKENs (SHAKEN) is an industry framework for managing the deployment of Secure Telephone Identity (STI) technologies with the purpose of providing end-to-end cryptographic authentication and verification of the telephone identity and other information in an IP-based service provider voice network. This specification defines the framework for telephone service providers to create signatures in SIP and validate initiators of signatures. It defines the various classes of signers and how the verification of a signature can be used towards the mitigation and identification of illegitimate use of national telecommunications infrastructure and to protect its users.
  3. Technical Report on a Framework for Display of Verified Caller ID. The Technical Report on a Framework for Display of Verified Caller ID provides a framework for signaling verified Caller ID information from the network to a User Equipment (UE), and displaying the information on the UE in a uniform manner, independent of technology. The goal is to produce display guidelines that help meet the goals of regulators and consumer protection agencies for empowering consumers with simple and effective information on the displayed Caller ID. This will help consumers know if a call is from who it says it is from so they can make an informed decision on whether to answer.
  4. Technical Report on SHAKEN API for a Centralized Signing and Signature Validation Server. The Technical Report on SHAKEN API for a Centralized Signing and Signature Validation Server provides additional detail on one possible implementation of the SHAKEN specification in service provider networks. It defines a RESTful interface (API) that can be used in the SHAKEN framework to interface with a centralized server to sign and verify telephony identity for multiple nodes within a network. Implementing SHAKEN authentication and verification functions in a centralized server that can be accessed via an API supports cloud-based implementations and is designed to enable a more cost-effective network deployment.
  5. Technical Report on Operational and Management Considerations for SHAKEN STI Certification Authorities and Policy Administrators. This document provides operational and management considerations for the Certification Authorities with the SHAKEN Governance Model and Certificate Management framework. It introduces considerations for the STI Policy Administrator in managing the list of valid STI CAs and authorized Service Providers, as well as general operational and policy considerations for PKI. This document introduces those aspects which are unique to the SHAKEN use of PKI.
  6. Joint ATIS/SIP FORUM Technical Report – IP NNI Profile
    This is the ratified version of the IP NNI Profile Specification, published by the joint ATIS/SIP Forum NNI Task Force. The IP-NNI Profile Specification defines a reference architecture and specifications for both the protocol and media as it appears “on-the-wire” at interconnect points. The specifications reference commonly used IETF, 3GPP, and other related industry specifications and identify protocol extensions and capability information needed for all-IP telephony peering.
  7. Joint ATIS/SIP Forum Technical Report – IP Interconnection Routing
    This is the ratified version of the IP Interconnection Routing Report, published by the joint ATIS/SIP Forum NNI Task Force. The IP-NNI Routing Technical Report documents mechanisms for identifying the preferred IP interconnection point for a given TN. This report presents multiple views of current IP interconnection mechanisms based on aggregate PSTN constructs, interim solutions based on all-IP routing using a per-TN registry, and a consideration of hybrid approaches across both mechanisms during the transition to all-IP.

NNI Task Force SHAKEN Presentations

Please find below a sampling of presentations about STIR/SHAKEN-related topics that are available for download:

  1. Overview of the STIR / SHAKEN Framework and Current NNI Task Force Milestones. This presentation was given by Martin Dolly, AT&T, and Co-Chair of the NNI Task Force during SIPNOC 2019.
  2. Overview and Update of the Secure Telephone Identity Governance Authority. This presentation was given by Presented by Linda Vandeloop, AVP External Affairs/Regulatory, AT&T and Chair, STI Governance Authority, during SIPNOC 2019.
  3. Operational Aspects of the STI-PA Policy Administrator including lessons learned on Certificate Management.. This presentation was given by Mary Barnes, SIP Forum, during SIPNOC 2019.
  4. Call Validation Display Framework: Challenges and Opportunities. What Do We Show to the Consumer?. This presentation was given by Richard Shockey SIP Forum Chairman, during SIPNOC 2018.
  5. Considerations Surrounding Enterprise Delegated Certificates. This presentation was given by Chris Wendt, Principle Architect, IP Communications and Services, Comcast, Director, SIP Forum, and Co-Chair of the NNI Task Force, during SIPNOC 2019.
  6. Introduction to Digital Signatures, Certificates and PKI.. This presentation was given by Russ Housley, Principal, Vigilsec, and Co-Chair of the IETF STIR WG. STIR / SHAKEN Working Group during SIPNOC 2018.
  7. SHAKEN and STIRed: Thoughts on the Current State of: Anti Spoofing / Caller Validation / Robocall Mitigation / Call Validation Display. This presentation was given by Richard Shockey during the Ribbon Communications STIR-SHAKEN Summit, March 2019.
  8. Full Attestation Alternatives for Enterprises and Business Entities with Multi-Homing and Other Arrangements. Presented by Gary Richenaker, Principal Solutions Architect, iconectiv during SIPNOC 2019.

For additional presentations, please visit the archived SIPNOC 2019 agenda webpage. Please note that the titles of each agenda item are hyperlinked to the associated presentation.

FCC and Other Regulatory Actions Regarding Robocalls and Caller ID Spoofing

Robocalls and telemarketing calls are currently the number one source of consumer complaints at the FCC.What was once a nuisance has become a plague to U.S consumers receiving an estimated 2.4 billion robocalls per month in 2016.

The FCC has been encouraging service providers to offer call blocking solutions that give customers greater control over the types of calls they receive. Call blocking is one part of the robocall solution. Another part is identifying the bad actors who use robocalls to take advantage of unsuspecting consumers by using numbers assigned to others (spoofing). They use cheap and accessible technologies to spoof their caller identity and scam victims with threats from the IRS, offers of loans, or free travel. The Strike Force is committed to protecting customers, but these disguised calls have put investigators and enforcers at a disadvantage.

Although several providers and third parties offer call blocking and caller identification verification products, there is no ubiquitous solution that spans wireline and wireless communication networks. The industry has been called to action by the Robocall Strike Force to collaborate on creative solutions to this ever changing problem.

The mission of the cross industry Strike Force is to accelerate the development and adoption of new tools and solutions to abate the proliferation of illegal and unwanted robocalls, to promote greater consumer control over the calls they wish to receive, and to make recommendations to the FCC on the role government can play in this battle.

The following information related to the FCC’s Robocall Strike Force and other FCC and FTC regulatory, and U.S. legislative actions include:

SHAKEN in the News

For More Information

For more information about the NNI Task Force, and the work in progress, please visit the ATIS/SIP Forum NNI Task Force Charter.

You can also access NNI Task Group announcements as follows: