VoIP calls – Protect your VoIP device and services

Voice over Internet Protocol (VoIP) is a way of transmitting telephone calls over the internet. With effective protection, VoIP services are safe and easy to use.

VoIP terminals include fixed telephone equipmentdevices, software used on a mobile phone or computer and traditional fixed-line telephones that have been connected to a VoIP service with a separate adapter.

Risks involved in VoIP services

A VoIP terminal device has to be protected against misuse. If a terminal device is not adequately protected, criminals may use it unauthorised to transmit international calls or calls to expensive premium-rate service numbers.

A subscription that is misused may quickly cause its holder damages worth thousands of euros.

In addition to misuse, VoIP traffic involves the risk of eavesdropping. Eavesdropping is easiest when VoIP calls are made in a wireless network (e.g. an unencrypted WLAN).

Protecting a terminal device

You should protect your VoIP terminal device with a firewall. The easiest way to do that is to use the device's own firewall. If you use VoIP software on your computer, the computer's own firewall is efficient. In the settings of the firewall, only allow VoIP connections to the servers of your service provider.

In addition to using a firewall, you have to keep the software of the VoIP terminal device and/or VoIP software up-to-date. Check regularly whether new updates are available. You can do that by visiting the device or software manufacturer's website or by using automatic updates.

Passwords, barring services and balance limits

Remember to change the default password of the VoIP service immediately when you start using the service.

Ask your service provider about barring services and other limitations available.

If you receive an unusually large invoice or believe you have fallen victim of unauthorised use, contact your service provider's customer service immediately.

Information security advice for VoIP services

Key words: Information security , Internet , Telephone

Updated 09.11.2017

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The Finnish Communications Regulatory Authority (FICORA)

The National Cyber Security Centre Finland (NCSC-FI)

P.O. Box 313, FI-00561 HELSINKI

Dynamicum, Erik Palménin aukio 1, 00560 HELSINKI

Media contacts by telephone +358 295 390 248