The way we communicate has changed several times since the invention of the telephone, but most of the times we were only dealing with variations on the same theme: automated switchboards, digital telephony, cellular telephony. But now there's a new standard emerging in telecommunications: VoIP.

VoIP, or Internet telephony, has been rapidly growing in popularity the past few years. It seems to have come at a very opportune moment, since broadband is more and more often people's preferred way of connecting to the Internet, and since most Internet users are already familiar with instant messaging programs.

The advantages of VoIP over traditional telephony are by now well known. Two main reasons are driving people and companies to subscribe to the service: the low calling costs and the impressive number of attractive features included for free in the VoIP package.

We mentioned instant messaging above because instant messenger programs were the first to offer VoIP over the Internet. Dialpad and Skype are two of the best known downloadable programs offering free calling. In time, however, with the impressive increase in both quality and demand, Pc-to-phone calling is not free anymore, or at least not unlimited (Dialpad will still let you call for free, but only in the U.S. and Canada, and the duration of each call is limited to 10 minutes). However, the fees are quite small.

Other instant messaging programs have added VoIP capabilities to their offer and allow users to make free calls between computers, as long as both participants run the same type of messenger: Yahoo Messenger, MSN Messenger, Google Talk, ICQ, and AOL Instant Messenger are the most popular. You'll need a broadband connection to get the best out of VoIP, but other than that, there are no special preparations needed. You just download one of these programs, connect a headset or speakers and microphone to you PC, and start calling your friends who use the same program.

If you like your Internet calling experience, you might want to subscribe to VoIP services. Not surprisingly, there are many providers and offers differ from one to another. Some will even give you unlimited calling plans in exchange for a monthly fee. It is important that you do some research and comparison of the different rates charged and services included, so that you will eventually find the most favourable one for you.

If you want to use your phone with VoIP, you'll need a VoIP adapter which will connect to your standard telephone and to the Internet. Another choice would be to purchase a VoIP phone, which is specially built for Internet telephony. They will usually have the same features as a complex desktop telephone, such as multiple lines, programmable keys, mute and hold facilities, and so on.

The enhanced efficiency of VoIP compared with PSTN is also proved by the many companies deciding to replace their telecommunications infrastructure. Statistics show that customer service response can increase by up to 50% as a result of the streamlining capabilities of VoIP. Integrated Voice Response systems enable seamless routing of calls to the department and the agent that is most suitable for handling them. Furthermore, the ability to incorporate audio, video, and web-based features into one application is another productivity catalyst. Adding new phone lines is much simpler than in the case of PSTN - and if you have a wireless network, things are even easier.

VoIP is a particularly attractive solution for call centres. There is no more need for all agents to be located in the same place. By employing people from different time zones, the centre can provide 24-hour support to its customers.

If VoIP continues to develop at the same rate - and there are good reasons to believe that it will -, PSTN might soon become associated with the 20th century, leaving the 21st to Internet telephony.