In its basic form, VoIP can only be used to communicate with other VoIP users. For many of us, that’s perfectly adequate; if we want to call anyone who doesn’t have VoIP, we can use our landline or mobile phone instead. However, there are services available (called ‘PSTN gateway services’), which provide the ability to make and receive calls to and from conventional phone numbers.
PSTN gateway service providers (often just called VoIP providers) provide you with this ability to call ‘real’ telephones. Your chosen VoIP provider will provide you with a telephone number that will allow other people to call you on your VoIP phone, as well as allowing you to dial out to conventional phone numbers.
Of course these services are not free - charges may be provided on a per-minute basis or at a flat monthly rate. Payment may be made via credit or debit card, or using a prepaid charge card system.
In general, calls made to conventional numbers through a VoIP provider will be significantly cheaper than calls made using an ordinary landline or mobile phone. In particular, many providers offer excellent rates for international calls. Skype, one of the largest VOIP service providers, even allows you to have several numbers in different countries. So a friend in the United States could call you on your US number (even though you are in the UK) and avoid paying for an international call.
It’s tempting to think that, once you have an account with a VoIP provider, you’ll be able to switch completely to using VoIP. However, it is important to note that most VoIP providers do impose some restrictions; for instance, you may not be able to call the emergency services or certain international locations, and operator services are unlikely to be available. Another issue is that your VoIP system will probably not work in the event of power failure. For reasons such as these, many people choose to use VoIP in addition to (not instead of) conventional phone services. And of course if you’re an ADSL broadband user, you?ll still need to keep your landline, because it is used for your Internet connection.
