Skype

More than 160 million people throughout the world have downloaded Skype’s software, which allows users to conduct voice calls using their internet connection.

Pros: The basic service allows people to talk to other Skype users free of charge, wherever they are in the world, using a headset that plugs into their computer. Users can also call fixed and mobile telephones in other countries at a reduced rate using SkypeOut, a service that routes phone calls through the internet network as far as the receiver’s local telephone exchange and then transfers it to the traditional telephone network. Calls to Europe, North America, Australia and much of Asia cost just over 1p per minute. Another service, SkypeIn, gives users a landline telephone number that links to their PC, and allows users to pick the apparent geographical location of their number. For example, a Londoner with a lot of American friends could choose a New York number, allowing contacts across the Atlantic to call them without incurring international charges. The call is then routed over the internet to the receiver’s PC. Numbers are sold on a subscription basis for about £20 per year.

Cons: Users can only make and receive calls when their computers are switched on and they are logged in to Skype. Another problem is that the system cannot be used to make 999 calls because the non-geographical nature of the network means that the automated emergency calls system cannot determine which local dispatcher should receive the call.

Vonage

Vonage works on a similar principle to Skype, but has added many features designed to position it as a replacement for the traditional phone system.

Pros: Unlike Skype, Vonage uses standard telephone equipment and does not require a computer to establish the connection. Using an adaptor, the phone is plugged into the broadband socket and the mains and calls are made and received in the usual way. There is a subscription charge of £9.99 per month (similar to BT’s £10.50 monthly line rental), which includes unlimited calls to UK landlines and other Vonage users, wherever their location. The price of other international calls varies, but rates for most countries are less than 2p per minute. Vonage can be used to dial 999 – emergency operators will ask for the caller’s location before transferring the call to the appropriate local service. Users can also use their phone adaptor overseas, wherever there is a broadband outlet, and avoid paying international rates for calls back to the UK.

Cons: Vonage cannot be used in a power cut, because unlike the standard telephone network, broadband internet lines do not provide power. Power for the Vonage system comes from the mains.

Instant messaging systems

Google Talk is the latest instant messaging service to offer the option of sending speech over the internet, but many other companies, including MSN, AOL, Yahoo! and BT, offer similar services.

Pros: All these services offer the software free of charge and allow unlimited text and voice conversations with anyone who has the same system, wherever they are in the world.

Cons: Like Skype, messaging services are intended to supplement home phones rather than replace them, as they only work while users have their PCs switched on and they are logged in to the service. The services are incompatible, so unless everyone opts for the same version users may need several different windows open to speak to all their friends and, unlike with Skype, there is no option to break out of the network and make calls to landlines.

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