VoIP Basics


This article was published by ComputorEdge, issue #2812, 2010-03-19, as the cover article, in both their PDF edition (on pages 6-9) and their website.

One can think of the Internet as a global computer network that is perfectly suited for the worldwide distribution of any type of digital information, whether it be text and images on a Web page, computer programs downloaded from a shareware site, e-mail messages, and audio — to name some of the most common types in use. That last category, audio, encompasses a wide range of formats and purposes. Examples include two-second notification sounds designed to provide user feedback on a website, and two-hour podcasts dedicated to the latest political news and commentary.

But what about what may be the most common form of audio information in the life of the average human: two-way conversation? Ever since the Web opened the door to the transmission of multimedia content in real-time, communications enthusiasts have been intrigued with the idea of digitizing human conversations, and transmitting them over the Internet, in real-time. They asked themselves, could the Internet be used to enable conversations that would otherwise be limited to telephone networks (either over landlines or wireless networks)?

Early efforts confirmed that Internet-based telephony was a real possibility, as a result of the Internet's underlying technology: Internet Protocol (IP), which is a set of agreed-upon rules for transmitting data over a computer network, by organizing that data into small pieces, referred to as "packets". In fact, Internet Protocol is what makes this ubiquitous platform as reliable and "self-healing" as it is, because TCP/IP directs the digital traffic along the most efficient pathways, automatically routing around digital "traffic jams" in the network, even completely unresponsive nodes, or any other problems.

The use of the Internet for transmitting phone conversations is predicated on packet voice technology, which got started back in 1993, through the pioneering work of Alon Cohen and Lior Haramaty, who at the time were part of the Israel Defense Force, and later founded their company, VocalTec Communications. But like so many other revolutionary technologies with profound implications (especially for those big old phone companies!), Internet telephony did not begin making significant headway until years later. In the United States, that wasn't until the early 2000s, when high-speed Internet access began to reach critical mass throughout the land. During the 1990s, most people were still connecting using dial-up Internet services, which were relatively slow and thus did not provide adequate throughput for digitized voice communications.

Speaking on the Net

Because this exciting new technology involves transmitting voice data using the Internet Protocol, it quickly became known as "voice over IP", or VoIP for short. It essentially comes in two flavors. In the more expensive of the two options, customers can connect their regular phone handsets to a special VoIP adapter, which digitizes their voices in conversation, and sends that information over the Internet, using high-speed connections (cable, DSL, and even satellite), completely bypassing the POTS ("plain old telephone service"). A customer's voice data is sent to a "VoIP gateway", which is a server located within the local calling area of the other party in the conversation. The gateway converts the digital voice data into analog sound, which the recipient hears using his or her regular telephone. To both parties, it appears to be a local phone call, regardless of the individuals' locations on the planet. Yet neither one of them must have, or be paying for, local phone service.

Vonage (pronounced VON-uj) is perhaps the best-known example of such VoIP service providers. At this time, they offer three different plans. The most popular one costs $24.99 per month, and allows subscribers to make unlimited local and long-distance calls anywhere within the United States and Puerto Rico, as well as free landline calls in more than 60 countries. The company's Pro plan, at $34.99, includes Canada in the unlimited long-distance calls. For those on a budget, the Residential Basic 500 plan, at $17.99, offers 500 minutes of outbound local and long distance calling to anywhere in the United States, Puerto Rico, and Canada, with additional minutes costing extra.

Note that all of these prices require one-year contracts. In addition, the company's website does not clearly indicate whether or not those prices exclude any regulatory, equipment, or activation fees — as they certainly did a few years ago. If those costs are not included, then they could add up over time, just as they do with conventional, non-VoIP service providers. One advantage to Vonage is that their specialized adapter is apparently quite diminutive and portable, which would be ideal for anyone who travels frequently but is able to get access to a high-speed Internet connection. This and other features have made Vonage a favorite, with the number of subscribers going from zero to 2.5 million during the five years after their inception in 2003. However, that number has leveled off during the past two years, quite possibly because of the next type of VoIP service that we will discuss (in addition to the even greater popularity of wireless phone plans and the handy smartphones that make it all possible).

While VoIP services that charge for calling to a landline or cell phone, can be a big improvement over POTS, an untold number of computer users are opting instead for services that enable communication directly back and forth between two (or more!) computers, thus eschewing regular telephones completely. Without a doubt the most well-known example of this is Skype, which currently offers several plans — some free and others not — with various features. If all the participants in a conversation are happy with using their own computers and Internet connections for the call — as well as headsets and/or speakers — then they can do so free of charge, and be able to send voice, video, and instant messages to one another.

Admittedly, there are countless people out there who have never heard of Skype, or for some reason do not want it installed on their computers, or do not even own a computer. Skype undoubtedly foresaw this impediment, and introduced services whereby Skype customers can make local and international calls to regular phone numbers (landline or wireless). This service is similar to that of Vonage, because the sender's voice data is transmitted over the Internet to the recipient's location, where it is converted into a local phone call. Any call from your computer to someone else's landline or mobile phone, costs a bit more than two cents per minute — which is quite reasonable, and avoids the extra fees with conventional phone service. If you want to do away with a regular phone number altogether, you can pay Skype $18 for three months (or $60 for half a year) and be able to receive incoming calls from any caller. They offer additional features, such as voicemail, forwarding, SMS messaging, and transferring to your regular phone — all at extra cost.

Your Computer As a Phone

There are a number of factors that could influence someone's decision as to whether to try out a VoIP service, and how successful the experience might be. For instance, Skype or any similar computer-based provider, would not be an option for anyone without a computer. But nowadays, at least in industrialized countries, that's probably a minority of the citizens.

The other hardware required for using VoIP, naturally depends upon what provider you choose; but in most cases it will include a handheld or headset microphone for transmitting your voice, and a stand-alone computer speaker(s) for listening to everyone else in the conversation, or one or more headset speakers. Personally, I prefer to use an Andrea NC-8 ultralight head-mounted microphone for input, and Harmon/Kardon HK195 powered stereo speakers for output. Neither component is top-of-the-line, but more than adequate.

When using Skype, your voice quality, as perceived by your listener, is determined by a number of factors — such as the quality of your microphone, whether it is well positioned close to your mouth (but not directly in the airstream), the upload speed of your Internet connection, the download speed of your listener's connection, the number of lost or delayed data packets, the quality of your listener's speakers, and any background noise in her environment. These are the major hardware and environmental considerations — any of which could be overwhelmed by human factors, such as how well you enunciate, how fast you speak, and your listener's hearing abilities.

Upsides and Downsides

The advantages of VoIP are clear to anyone who has been using it for any length of time, and has invested in the proper hardware and also in learning how to make the most of it. Depending upon the number and duration of your phone calls — and of course whether they are local or long-distance — the money saved can be quite significant. In fact, with free or low-cost calling, you may end up making even more calls than otherwise, spending more time talking with friends and family, and enjoying the overall experience better than if you had stayed with an old-fashioned phone service.

Also, you can avoid getting locked into a long-distance plan, and paying all of those extra fees that seem unavoidable. It seems like only yesterday that when you moved into a new neighborhood and received a new local phone number, you had to choose a long-distance provider, and immediately your monthly phone bill was padded with all sorts of interstate fees, even if you had not made one long-distance call during that entire period.

Perhaps best of all, digital voice makes it much easier for companies to offer communication capabilities that were unheard in the past, such as converting audio messages into text, which can be sent to you as e-mail messages (a terrific feature of Google Voice). Digitization has also enabled transmitting real-time video between you and everyone else on the line.

But there are some disadvantages as well. For instance, emergency and technical support phone calls can be impossible with most of the VoIP providers, who typically warn prospects right up front that 911 calls are not possible. Of those providers that do offer emergency calling, you must reveal your physical address, because that is required by your local emergency services. A more likely potential problem is, what happens to your phone service when your Internet connection goes down? It of course goes down as well. And then how do you call your Internet service provider to report the problem and request that someone come out and fix it? Fortunately, there are usually neighbors and other people around, who have landline or cell phones.

Even though the VoIP voice quality is better than it was years ago when the pioneers first made it available, it still is not perfect. The cheapest providers typically have the worst voice quality, with slight delays in transmission, which can slow conversations. Yet proponents of VoIP can point out that its voice quality is oftentimes better than that of mobile phones, and the connections in general are more reliable, with no worries of a conversation being interrupted when someone drives into a tunnel or parking garage, or out of range of cell towers.

All things considered, most people who try VoIP find that the pluses are much greater than the minuses, and these folks usually become big fans of this new way of talking to people on the other side of the globe, or just the other side of the street.

Copyright © 2010 Michael J. Ross. All rights reserved.