Feature: Make free phone calls over the Internet

Skype extras

Possibly the biggest drawback to Skype, Yahoo and similar services is the reliance on software running on a PC, which needs to be switched on in order to make and receive calls.

You can cut the desktop tie with a notebook and there’s a Pocket PC version of Skype for even greater mobility, but neither of these come cheap, and what you save on calls you’ll spend on the hardware.

Fortunately, there’s a growing market for add-ons to help get around this issue, most designed to work with Skype, but some with other VoIP services as well.

For example, a number of vendors now sell telephone handsets to work with PC-based VoIP services. You can’t just plug these into your broadband modem, but they do let you connect to your PC and make and receive calls remotely from the comfort of your armchair.

The cheapest Skype handsets (around £23) plug into a USB port, and there are lots of products to choose from, such as the USB Internet Phone from US Robotics which costs £21.60.

Wireless models are also available, although they are a lot dearer. For example, the Linksys Cordless Internet Telephony Kit CIT200 uses a wireless Dect handset to connect to the host PC via a small USB receiver.

Completely standalone implementations of Skype and other VoIP clients on mobile handsets are also on their way. Netgear, for example, has announced a Wifi phone with Skype software that should be available later this year, and others are likely to follow.

You can also get software add-ons for Skype, from your own voicemail recorder to tools to forward calls and integrate Skype into a website or blog.

A number of Skype-based services have also sprung up to further help break the reliance on a host PC. One such service is EQO, which lets you use a mobile phone to connect to your PC and make Skype calls by selecting from an on-screen ‘buddy list’.

The Sip alternative

Services such as Skype, MSN and Yahoo Messenger certainly have a great many benefits. They’re easy to set up, simple to use and cheap, with millions of users worldwide.

However, they do tie you into a proprietary technology, which means you’re totally reliant on a single provider for the service you get.

There’s also the reliance on a PC, and the fact that free calls are only available when you talk to people using the same service. But these issues won’t apply if you opt for a standards-based alternative.

With standards-based VoIP, you’re no longer tied to a PC, with a wide choice of hardware available to make and receive calls including analogue phone adapters, VoIP-enabled routers and specialised desktop and wireless IP phones.

You can also mix and match products and, if you’re not happy with a service provider or find a cheaper one, you can switch.

On the downside, a number of different VoIP standards have been developed, which can be confusing. However, the most widely adopted, and the one you’ll encounter the most, is Sip (Session Initiation Protocol).

A little technology

The vast majority of VoIP services are Sip-based, especially those aimed at the home user, and Sip itself is quite a simple protocol to understand.

In fact, it only handles the setting up of calls, leaving the voice encoding and encapsulation, for example, to other technologies.

To do this, Sip comes in two parts. A Sip client – such as a softphone on a PC or firmware embedded into an adapter or handset – and a Sip server, typically, hosted by a VoIP service provider.

The client regularly advertises (registers) its ‘presence’ with a so-called Sip registrar hosted by the server. This then tells the server that it’s switched on and available to make and receive calls.

The server also knows the IP address of the client, enabling it to route incoming calls to it and set up outbound calls on the client’s behalf (a Sip proxy), with facilities to connect to the PSTN via a gateway to handle incoming and outbound calls.

You don’t have to worry about the technical details of how it all works, as all you have to set up is the client. And a lot of the time that’s taken care of for you anyway.

Sip options

There are a number of different ways to get started with Sip, the easiest of which is to sign up for a complete bundled package.

Most packages will include both a subscription to the hosted VoIP service plus the necessary Sip-enabled hardware and software; for example, Freetalk, Plustalk or the recently launched Tesco Internet Phone package.

Take this route and you’re almost guaranteed to get a working solution plus, if problems do arise, they should be easy to resolve. Notice, too, that many of the broadband service providers also offer optional Sip-based voice products.

Some are available independently, such as Nildram Voice, while others are part of an overall broadband package, such as Freedom2Surf and Wanadoo Wireless & Talk. Either way, it’s worth checking with your current provider before looking elsewhere.

Alternatively, you can go it alone and source the client hardware or software independently, then connect it to one of the many VoIP services available.

Some are free to join and others require an up-front subscription, but all should allow you to make calls to other VoIP users without any charges.

Calls to the PSTN, however, will require the service provider to configure a gateway (just as with Skype), and most will charge for this facility.

Charges are usually on a pay-as-you-go basis, either billed in arrears or up front using credits that need to be topped up like a pay-as-you-go mobile.

Some, though, also offer inclusive calling plans where for a monthly fee you might get low-cost or even free UK local and national calls, plus discounted international and mobile rates.

Similarly, if you want to be able to receive PSTN calls, a gateway is required as well as a public telephone number.

Some service providers charge separately for this, some require a monthly subscription for the number and different rates may apply depending on whether you have a non-geographic number (with an 0870 prefix, for example) or a geographic number from a specific exchange.

You may also be able to choose any exchange in the country, with some providers even offering international numbers.

Costs vary considerably, and it’s advisable to do a fair amount of research, so check out our table of VoIP services for sample costs and calling rates.