What is IP telephony?

Voice over IP (VOIP) means using the internet for phone-like conversations. In most cases, a computer is used at either end with a mike and speakers or headphones.

Increasingly handsets are available that let people replace traditional landlines and receive incoming phone calls from normal phones.

Companies providing these services include Skype and Vonage. See more services on DMOZ.

How to make VOIP safe

• Running your phone line through your broadband internet connection or PC means that it is even more important that your computer is secure. This means: anti-virus, anti-spyware and firewall software plus regular updates.
• VOIP works over public internet connections. This means that there is a small risk of eavesdropping. This makes it important to choose a VOIP provider who offers secure encryption on their service.
• In most cases you need a password to log in to a VOIP service. Because this is the only means of proving your identity, it is important to use a strong password and to keep it private (see Use strong passwords).
• Set up your service to allow connections only from people you know and block everyone else. This will prevent strangers cold-calling you.
• If your service includes a public profile, don’t put any sensitive, private or confidential information in it.
• Be aware that if you use a VOIP phone to replace a landline, it will depend on your broadband internet connection and a router to work. If there is a power cut or other problem with the equipment, you may not be able to call 999.
• As with all other software, check regularly with the company’s website to see if there are any updates or patches.

More information

• Skype's own guide to staying secure.