Free phone calls over broadband: VOIP explained

Originally published in GP magazine .

Written for GP magazine around 2006. This is the version I submitted - the published article may have been edited.

You may have seen the advertising which states free phone calls using your broadband and wondered if this was simply too good to be true. You may have heard about voice over IP (VOIP) and wondered what all the fuss is about.

VOIP is a way of making digital phone calls. When you ring someone on your normal home phone line, essentially you are directly connected to that person by a wire. All the exchanges and wiring are simply to connect your phone to the other person’s. Using digital equipment, your voice can be broken down into millisecond chunks and each chunk sent electronically via the internet as if it was an email or a webpage. The internet routes these packets of data from your location via several computers and networks to its destination.

Although in theory this works well, the quantisation of data creates several problems. For example, if the packets arrive in a different order to that in which they were sent, this needs to be corrected fast enough for you not to hear any dropouts or poor quality, and if you are downloading a large file there may be no room on your broadband link for the voice call to get through.

In a business on its own network, special routers are used which know the difference between voice and data and assign voice a higher priority, so internal calls are generally good quality. However, the internet at large doesn’t prioritise voice, so call quality can suffer, particularly if there is heavy traffic on the internet or you have numerous people sharing your connection. The good news is that as broadband gets faster and you can download more data at once, these problems are reducing.

In its simplest form these calls go from one computer to another, and both computers need to be on and running the right software. As long as the software is free, all you pay for is your broadband connection and the advertising is therefore true. One problem is that most of the companies’ software is incompatible with each other, so you can only call users of the same service. There are moves to make a universal standard but this hasn’t happened yet.

There are hundreds of companies providing this service; perhaps the best known is Skype, which was bought by eBay recently. If you go to their website you can download their software and, after installing it on your computer, register with their service. As long as your contact has done the same, you can type in their address and if their computer is on it will ring and you can speak to them. You will both of course need a microphone and speakers.

There are numerous enhancements available, some of which cost money. If the other person isn’t available you can leave voicemail, which they can collect. You can conference call to more than one person, and you can now buy handsets that plug into your USB port that you use like a phone. You can also text and, even, with the right equipment, make video calls.

Perhaps the greatest enhancement is the ability to place calls to and receive calls from normal phones. The company providing the software has a connection into the normal phone network, and you can ring a normal number and have it ring. The quality of these calls is the main issue and can be variable. It is also possibly too dependent on tweaking your setup to achieve best quality to replace normal phones completely just yet. However, in my experience it can be good given a fast enough broadband link.

The downside to ringing normal phones is that this isn’t usually free. Skype and Tesco charge you 2p a minute to UK landlines and also to many other countries, including the USA. In fact, if you regularly call abroad these phones are excellent value.

A new phone prefix has been allocated to these phones, and if you sign up for this service you will get a new phone number to remember. Friends with caller display get very confused for a while after you start ringing them, as they can’t work out where you are.

I signed up for BT’s deal. This gives you a box that plugs into both your home network and your home phone line, into which you plug a normal phone. You are allocated a broadband phone number which people can ring you on, and you can call either other broadband phones or normal phones. My call package gives free evening and weekend calls. Although it doesn’t do any of the fancy things that soft phones like Skype can, it works simply: pick up the phone and dial a number, and my PC doesn’t need to be on. Quality has been good, though occasionally the phone doesn’t work for no reason and needs turning on and off to reset it.

Overall, free calls can be made using the internet, especially if all your contacts sign up for the same service.