Peter Ford: Cross-Border Call Authentication Needs Improvement

Voice remains indispensable for global enterprises — even as messaging and apps now dominate the communications landscape — because banks, hospitals and retailers depend on real-time spoken interactions for critical operations. When calls fail to connect or are mislabeled as spam, the consequences ripple across balance sheets and customer relationships alike.

What’s changed in recent years is the infrastructure carrying those calls. Traditionally, business voice relied on the public switched telephone network (PSTN), but nearly a third of organizations now use VoIP delivered via broadband. This change introduces flexibility and scalability, but also makes call delivery dependent on complex, shared IP protocols and cross-network authentication, raising the stakes for global and cross-border reliability.

STIR/SHAKEN was supposed to change this; and to a degree, it has. In markets like the U.S., Canada, France and Brazil, authenticated traffic has mitigated spoofing and given communications service providers (CSPs) better tools to filter fraud. But the framework only works when both the originating and terminating CSPs are in sync. For most international calls, that simply isn’t the case.

As regulators and carriers crack down on illegal robocalls, the fragmented trust environment leaves legitimate cross-border calls – many of them VoIP running over broadband – at risk of being blocked or mislabeled as collateral damage.

The global enterprise problem

Enterprises that operate across borders have seen the effects first-hand. A U.S. bank that outsources customer support to the Philippines, for example, may find its outbound calls consistently tagged as “Spam Likely.” Whereas a European retailer following up on an online order with a U.S. customer may see their calls go unanswered. Even when calls do go through, recipients are primed to distrust them: 92% of consumers say unidentified calls are fraudulent, while nearly 80% won’t answer.

Since VoIP traffic typically traverses multiple networks and peering points, the probability of lower attestation levels increases, which trigger filter blocks. Each blocked or ignored call translates into lost revenue, wasted agent time and diminished customer confidence. For industries that depend on timely communications — finance, healthcare, logistics — the consequences are real.

In addition, broadband has blurred the line between “domestic” and “international” networks. A call may traverse multiple IP backbones before landing in another country. Without interoperable authentication, that flexibility becomes a liability rather than an asset.

Why 'C' attestation isn't always a scarlet letter

Part of the issue is the way attestation levels are applied across networks. Calls originating outside the U.S. and terminating in the U.S. – whether using numbers from the North American Numbering Plan (NANP) or not – often receive a "C" attestation, which signals doubt about the caller’s identity. This status can reflect limited international cooperation or the complex, multi-network paths common in broadband VoIP systems, causing even legitimate calls to be mislabeled.

Receiving a "C" attestation does not inherently mean the call is fraudulent. Rather, it is an indication that the originating CSP does not have a direct, trusted relationship with the terminating CSP. Treating every call marked with "C" as suspicious oversimplifies the issue and can wrongly penalize genuine businesses alongside those engaging in fraud.

What it will take to fix this

Closing the authentication gap is both a technical and commercial imperative. Without it, global voice traffic becomes costlier, less reliable and less trusted—eroding a channel that enterprises still rely on for high-value engagement. As broadband penetration rises and VoIP becomes the default, the challenge only grows.

Progress won’t come from a single global protocol but from interoperable standards and extending trust across borders. Two priorities stand out:

• Cross-Border Call Authentication. Building on STIR/SHAKEN, carriers in different countries can exchange verified credentials and metadata over the same IP networks that carry their voice traffic. Rather than enforcing uniformity, this “global trust handshake” helps VoIP calls be validated wherever they originate.
• International Traceback. By tracing a call through the telecom and broadband ecosystem to confirm its source, traceback adds visibility and accountability. Combined with authentication, it helps CSPs separate fraud from legitimate traffic without blunt blocking.

This is more than a fraud problem—it’s an economic one. As such, CSPs, regulators and enterprises must coordinate to deploy these mechanisms and build a trust fabric that reflects today’s broadband and VoIP realities. If not, CSPs risk losing high-margin international traffic. Enterprises face rising customer-engagement costs. Consumers, conditioned to distrust calls, lose access to effective communications with the businesses they rely on.

A call to action

The industry has shown it can unite around standards. STIR/SHAKEN for robocall mitigation is a prime example. Now cross-border trust, tailored to a broadband—and VoIP—world, must be the next frontier. The path forward is clear: interoperable authentication, coordinated traceback, cross-border trust registries and regulatory frameworks that enable—not stifle—shared solutions. Achieving this will require the same level of collaboration and urgency that drove domestic efforts, but on a truly international scale; and in a broadband-powered, VoIP-first world, the stakes have never been higher.

Peter Ford is the Executive Vice President, Head of Information Solutions business for iconectiv. He is responsible for leading the platform portfolio for the company’s trusted communications. He previously served as the Managing Director, EMEA, Service Provider Transformation Group at Cisco Systems, where he developed partnerships with some of the largest global telecommunications players on issues such as Big Data/Analytics and Network Convergence and Security. This Expert Opinion is exclusive to Broadband Breakfast.

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