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Voice over internet protocol (VoIP)

Voice over internet protocol (VoIP)

Earlier, you saw PSTN and noted that it's a very old technology. Nowadays, instead of PSTN, many telephones and devices use VoIP technology to make calls via the internet.

The primary risk associated with Voice over IP, like Zoom and Microsoft Teams, is interception of traffic.

Hacks usually happen when one of your employees accidentally gives information to a scammer. These types of social engineering scams account for 97% of all malware attacks.

For example, hackers target people working in customer service and in the Network Operations Centre (NOC), acting as someone else. Without realising, staff can give unauthorised access to the hacker, who then takes control of your VoIP phone system.

Access to your organisation’s phone system can allow the hacker to launch other attacks. For example, a VoIP hack could access the financial details, impersonate your company, and access private customer information.

Hackers can also use your company phone service to commit fraud. They can make calls using your VoIP system and your caller ID will show. They can then impersonate your company to scam customers out of their private information.

Man on VoIP call in office. Colleague at same desk in background.


Countermeasures can include:

  • Separating the Voice over IP traffic from data, for example using VLAN technology.
  • Encrypting Voice over IP traffic during transport over the IP network.
  • Using secure Voice over IP products, which can be assessed prior to implementation.
  • Training and education.

What's next?

Next, you're going to look at CCTV and teleconferencing systems and the risks and defences involved.


In this Course, you’ll further explore the web protocols that underpin the internet and the world wide web, and some of the applications they enable.

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