Call Guardian Authentication Hub

TNS Call Guardian Authentication Hub is a managed end-to-end call authentication solution that analyzes real-time call events combined with STIR/SHAKEN authentication and validating the caller ID that allows operators to differentiate between legitimate users of communications services versus abusive, fraudulent and unlawful users.

TNS Call Guardian Authentication Hub is an integrated solution powered by TNS and Metaswitch. It includes TNS’ Call Guardian analytics and robocall detection engine and Metaswitch’s MetaSphere QCall SIP application server.

Robocalling Epidemic

The FTC received 3.7 million robocall complaints in 2018. Robocall bad actors continue to adjust their strategy to elude detection. The time is now to improve your subscribers’ call experience.


STIR and SHAKEN use digital certificates, based on common public key cryptography techniques, to ensure the calling number of a telephone call is secure. STIR/SHAKEN will identify Caller ID spoofing, a common technique used by robocallers, by authenticating the Caller ID at the origination point of the call, then validating this Caller ID at the termination point. Operators can use STIR /SHAKEN, in conjunction with Call Guardian real-time analytics, to determine the validity and intent of a call.

Regulators are increasingly applying pressure to carriers to solve the robocalling problem. In the US, FCC Chairman Pai sent letters to 11 voice providers asking those that had not yet established concrete plans to implement the Signature-based Handling of Asserted Information Using toKENs (SHAKEN) framework and the Secure Telephone Identity Revised (STIR) standards to implement such standards without delay. In Canada, the CRTC has mandated deployment of STIR/SHAKEN.


Key Features

Managed Solution

Available as a fully managed hosted solution.

Real-time Robocall Detection

Call Guardian Authentication Hub detects problems as they occur.


Full compliance with standards in ATIS test bed:

  • STIR: RFC 8224, RFC 8225, RFC 8226
  • SHAKEN: ATIS 1000074, ATIS 1000080, ATIS 1000082

Managed Service

Management of private keys and signing for authentication.


Analysis of over 1 billion call events daily across more than 500 operators.

Reputation Profiles

Caller reputation on over 1 billion telephone numbers.

Layered Approach

Support for DNO, invalid, unallocated, unassigned numbers, STIR/SHAKEN and big data analytics using machine learning.


Key Benefits

Meet FCC Requirements

Call authentication framework that complies with direction for Tier 1 providers.

Reduce Network Costs

Block calls in the network allowed by the FCC, reduction in CNAM costs.

Engagement Platform

Network-level solution that can be leveraged for branded calling and enhanced caller ID.

OPEX-based Model

Cloud-based solution that scales up and down to any size network.


Ingests parameters from STIR/SHAKEN to provide improved call management for your subscribers.

Ubiquitous Solution

Supports multiple network protocols (SIP, AIN, IMS, NGN) and integrates with all major network elements.


TNS Robocall Report March 2020

The 2020 Robocall Investigation Report by TNS includes a vast amount of factual evidence derived from real network traffic over the last four years. The study is unique in that it offers an objective, first-hand view of robocalling, spamming and spoofing across the hundreds of carriers that signal across the TNS signaling and database routing infrastructure. 

To download the report click here.