Businesses continue to underestimate the security risks embedded in modern voice networks. Too many treat voice services as simple telephone calls rather than as complex IP-based systems exposed to the same threats as the rest of their digital infrastructure.

According to Peter Bokaba, network manager at Centracom, this misconception is leaving organisations vulnerable to voice fraud, where attackers exploit weaknesses in Voice over IP (VoIP) environments and on-site telephony systems to generate unauthorised and costly international calls.

Voice networks are not ‘just calls’

Bokaba says the core risk lies in how easily business voice systems can be compromised when basic protections are not in place. “When Voice over IP devices or PBXs are compromised, attackers can generate fraudulent calls to expensive international destinations that they own, control or financially benefit from through revenue-sharing arrangements,” Bokaba explains. “A business that normally sees a R10 000 monthly bill can suddenly face charges 10 or 20 times higher if systems are accessed without proper controls.”

Fraudsters often rely on automated scripting tools to repeatedly attempt logins or exploit exposed systems at scale. Once access is gained, they can route calls through premium-rate or high-cost international destinations, rapidly escalating costs for the victim organisation.

How to protect your voice systems

Bokaba notes that while some risks begin with basic vulnerabilities such as weak credentials or exposed systems, modern voice infrastructure requires a layered approach to security.

“At a practical level, businesses should ensure simple but critical housekeeping is done, like regularly updating credentials,” he says. “Beyond that, we implement additional controls such as encrypted tunnelling, IP-based authentication and network segmentation to ensure voice systems are not directly exposed to the public internet.”

Centracom also highlights the importance of proactive monitoring and threshold-based controls that can flag or restrict unusual calling behaviour before significant losses occur. These include automated alerts and safeguards that can restrict international routing when abnormal activity is detected. Says Bokaba: “What matters is educating businesses about what voice fraud actually is, because most organisations still think of voice as a simple utility rather than part of their digital attack surface.”

A growing but misunderstood threat

Bokaba says the focus now is on raising awareness of these risks while applying practical, proven safeguards that reduce exposure to fraud and unauthorised usage. Rather than positioning voice security as a niche or emerging discipline, the company argues it is now a fundamental part of network governance – one that deserves the same operational discipline as any other critical IT system.

As Bokaba concludes, the goal is straightforward: “It’s about ensuring that what looks like a simple phone call is actually protected as part of a much more complex and valuable network environment.”

Learn more at centracom.co.za or connect on LinkedIn.