What Does VoIP Mean?

In spite of the massive proliferation of VoIP throughout the consumer and enterprise markets, not many people truly understand what VoIP means and how it works.

It is also sometimes called Internet telephony, broadband phone service, IP telephony and many other terms. VoIP is an acronym that stands for Voice over Internet Protocol.

As the name would suggest, VoIP is a group of technologies that allows for voice to be transmitted over the Internet rather than through the PSTN.

Although VoIP providers also offer related services like sending messages or videoconferencing, its essential function is to power voice calls.

The fundamental difference between normal phone calls and VoIP is that the latter evolved from IP-based technologies rather than telecommunication standards.

Similarities Between VoIP and PSTN

Making a VoIP call requires some of the same steps as a traditional phone call. Some of the processes involved are signaling, channel setup, session teardown, encoding etc.

Apart from that, the user experience remains largely the same. Most hardware-based IP phones also look and feel the same as regular phones. Users do not need any training to make VoIP calls, although VoIP deployment within an enterprise requires technical knowledge and expertise.

Many of the same features that were long since available on PSTN lines are also present on VoIP networks such as voicemail, conference calls, faxing etc.

Differences between VoIP and PSTN

VoIP calls are transmitted over the Internet while PSTN calls are transmitted using TDM circuit switches. VoIP is much more efficient and less expensive when compared to analog calls.

It is also much more flexible and compatible with the latest generation of Internet-based technologies, unlike the PSTN. Advanced features of VoIP include visual voicemail, caller groups, online dashboards etc.

Since VoIP is based on IP protocols, innovation is much faster when compared to PSTN. Although it is relatively new, there have already been vast improvements in the technology, network, hardware and software from the earliest generation deployments.

Internet Protocols, Audio codecs and QoS

VoIP can be implemented using open source standards or proprietary protocols.  Session Initiation Protocol is the most widely used but there are others like H.323, MGCP (Media Gateway Control Protocol), Real-Time Protocol (RTP) etc.

In addition, there are several other standards that are used for streaming audio/video or for specific deployments and configurations.

Audio codecs serve an important function in VoIP telephony – these are the software bits responsible for converting audio signals into digital data and vice versa.

The audio codecs are the reason phone calls can be transmitted over the Internet just like any other piece of media like email, documents, images etc.

In addition, the codecs are also responsible for compressing the data to save bandwidth. Hence most codecs have two important aspects – high quality audio and bandwidth usage.

Some codecs compress the data to conserve bandwidth so that large number of simultaneous calls are possible.

However it often comes at the cost of audio quality. On the other hand, there are several codecs that offer high quality audio but in turn take up a lot of bandwidth.

As Internet connections become faster and cheaper, bandwidth usage may cease to be a concern. But until then, enterprises will need to strike a balance between quality and data use.

Since VoIP uses the Real-Time Protocol, there is no guarantee that all the data packets will reach the destination or that they will be in sequential order. RTP was chosen because it is fast but lacks guaranteed delivery.

This is why VoIP is perceived as being less reliable than the PSTN network. In general, VoIP faces issues with latency, jitter, lag and other packet issues. As a result QoS or Quality of Service is a very important term in VoIP.

Normally the QoS settings determine the quality of the call, prevent disruptions or dropped calls and maintain the phone connection even when the network is congested.

In many corporate deployments, faulty QoS is the reason for poor quality VoIP calls even though the network may have high-speed Internet access and other prerequisites.

Is VoIP Useful?

In some ways the appearance of VoIP technology seems inevitable. The human population across the globe is increasing rapidly and business environments are constantly changing thanks to cloud technology, Internet, social media and other trends.

The old PSTN networks were not really able to cope with the new digital reality. VoIP is more cost-effective, flexible, innovative and efficient.

For the average consumer, switching to VoIP can save hundreds of dollars per month in phone bills – especially long-distance or international calls. Corporations can also see tremendous cost savings but VoIP has even more attractive benefits for businesses.

VoIP allows an organization to connect all its employees – regardless of location, time zones, device and computing platform.

The new reality of telecommuting, employees working from home, mobile workspaces and business activity is best supported by VoIP. It is no wonder that VoIP usage is steadily increasing across much of the world.