What is VoIP?

VoIP allows the user to make telephone calls using a computer or data network such as the Internet.

In a traditional telephone call, voice data flows over circuit-switched phone lines owned and operated by your phone company and interconnected to other phone company lines all over the world. A circuit or “pipe” between you and the person you are calling is opened and stays open for the duration of the call. No one else can intrude upon that circuit and use it while you are using it. This technology for making phone calls is old school—it’s been around for over one hundred years — and it is jocularly referred to as “Plain Old Telephone Service”, (POTS). The network that runs this service is called the Public Switched Telephone Network (PSTN).

Using VoIP, your voice conversation is digitised, (converted to data). In effect, your digitised voice call shares space with lots of other voice calls, email, data transfers, et al, and as a result is much less expensive to operate.
With VoIP, therefore, the signal from your telephone is converted into a digital signal, chopped up, and sent in “packets” over the Internet. Lots of packets from lots of sources use the same pipe that travels over the internet. It is then converted it back at the other end to finish its journey so that the user can speak to anyone with a regular phone number.

It is important to note that VoIP is not limited to voice communication. In fact, a number of efforts have been made to change this popular marketing term to better reflect the fact that VoIP means voice, video, and data conferencing. All such attempts have failed up to this point, but please do understand that video telephony and real-time text communication ToIP, for example, is definitely within the scope of the VoIP.

VoIP is important because, for the first time in more than 100 years, there is an opportunity to bring about significant change in the way that people communicate. In addition to being able to use the telephones we have today to communicate in real-time, we also have the possibility of using pure IP-based phones, including desktop and wireless phones. We also have the ability to use videophones, much like those seen in science fiction movies. Rather than calling home to talk to the family, a person can call home to see the family.

One of the more interesting aspects of VoIP is that we also have the ability to integrate a stand-alone telephone or videophone with the personal computer. One can use a computer entirely for voice and video communications (softphones), use a telephone for voice and the computer for video, or can simply use the computer in conjunction with a separate voice/video phone to provide data conferencing functions, like application sharing, electronic whiteboarding, and text chat.

VoIP allows something else: the ability to use a single high-speed Internet connection for all voice, video, and data communications. This idea is commonly referred to as convergence and is one of the primary drivers for corporate interest in the technology. The benefit of convergence should be fairly obvious: by using a single data network for all communications, it is possible to reduce the overall maintenance and deployment costs. The benefit for both home and corporate customers is that they now have the opportunity to choose from a much larger selection of service providers to provide voice and video communication services. Since the VoIP service provider can be located virtually anywhere in the world, a person with Internet access is no longer geographically restricted in their selection of service providers and is certainly not bound to their Internet access provider.

- In short, VoIP enables people to communicate in more ways and with more choices.

Technical differences between VoIP and traditional PSTN.

Current phone networks are used for the same purpose as VOIP i.e. one person speaking to another. However PSTN networks need complex circuit switching to route calls to their destination. VoIP uses existing IP technology i.e. the internet or your network. It uses Packet switching to send information - directing only the “packets” of voice data to their destination.

This requires much less infrastructure than the old telecommunications technologies used in the UK - saving a considerable amount of money for the user. For businesses who want many lines they have to have these lines installed and routed through the building.

With VOIP they can often use existing network infrastructure and just increase bandwidth as they need to. You might not even need trailing wires if you are using a wireless network.

This technology has numerous advantages over the current system, mainly in cost reduction, but also in future capacity and capabilities. It would not be difficult to combine VoIP with other existing technologies such as streaming video.

Major telecom’s companies often use VoIP “in the middle” of the virtual connection of your phone call, especially in long-distance or transatlantic calls. Many users are unaware that their call is converted from PSTN (Public Switched Telephone Network) to VoIP and then back to PSTN to the receiver of the call.

For the home user with access to a fast internet connection or a small business thinking about implementing VoIP to save costs it is worth noting that while VoIP is undergoing rapid adoption by large companies and telecoms networks it still has some work to be done to make it accessible to all at economic cost.