VoIP 101: Voice over IP for Beginners
by: Rich McIver
For those who have never heard about the potential of VoIP, be
prepared to radically change the way you think about your current
long-distance calling plan. VoIP (Voice over Internet Protocol) is
very simply, a method for taking ordinary analog audio signals and
turning them into digital signals that can be sent over the
Internet.
So what? Well, for those of you who are already paying a monthly
fee for an Internet connection, this means that you can use that
same connection to place free long distance phone calls. This
process works by using already available VoIP software to make phone
calls over the Internet, essentially circumventing phone companies
and their service charges.
Interestingly, VoIP is not an entirely new thing. In fact, a
number of providing companies have been around for some time. But it
has only been with the more recent explosion of high-speed internet
access usage, that VoIP has gotten any attention. Now the major
telephone carriers are setting up their own VoIP calling plans
throughout the US, another testament to the potential of the
technology.
How VoIP Is Used
While there are a number of ways that VoIP is currently being
used, most individual callers fall into one of three categories:
ATA, IP Phones, and Computer-to-Computer.
ATA or Analog Telephone Adaptor, is the most common way of using
VoIP. This adaptor actually allows you to hook up the phone that is
already in your house, to your computer, and then your Internet
connection. What the ATA does, is turn the analog signals your phone
sends out into digital signals that can be sent over the Internet.
Setting up this system is quite simple. It simply requires that you
order an ATA (its an adaptor remember), plug the cable from your
phone which would normally go into the wall socket into the ATA, and
then the ATA gets plugged into your computer, which is connected to
the internet. Some ATAs include software that has to be installed on
your computer before its ready, but basically it's quite a simple
process. Then you are ready to make some calls.
The next type of VoIP usage utilizes IP Phones instead of your
home phone. The IP Phone looks just like a normal phone, with all
the same buttons and cradle, the only difference is that instead of
having a normal wall jack connector, it has an Ethernet connector.
This means, that instead of plugging in your IP phone to the wall
jack like you would with a regular analog phone, it gets plugged
directly into your router. This option allows you to circumvent your
personal computer, and it also means that you will not have to
install any software, because its all built in to the handset. In
addition, the fact that Wi-Fi IP phones will soon be available,
which will allow subscribing callers to make VoIP calls from any
Wi-Fi hot spot, make this option an exciting possibility.
The simplest and cheapest way to use VoIP is through
computer-to-computer calls. These calls are entirely free, meaning
no calling plan whatsoever. The only thing you need, is the software
which can be found for free on the internet, a good internet
connection, a microphone, speakers, and a sound card. Except for
your monthly internet service fee, there is literally no cost for
making these calls, no matter how many you make.
For large companies, VoIP also offers some very unique
possibilities. Some larger companies are already utilizing the
technology by conducting all intra-office calls through a VoIP
network. Because the quality of sound is comparable to and in some
cases surpasses that of analog service, some international companies
are using VoIP to route international calls through the branch of
their company nearest the call's destination and then completing it
on an analog system. This allows them to pay local rates
internationally and still utilize the same intra-office VoIP network
that they would if they were calling someone in the next cubicle
over.
Other Advantages of VoIP
While your current long-distance plan covers you for only one
location, say calls made from your office, with VoIP, you can make a
call anywhere that you can get a broadband connection. That is
because all three methods above, unlike analog calls, send the call
information via the Internet. This means you can make calls from
home, on vacation, on business trips, and almost anywhere else.
Anywhere you go, with VoIP you can bring your home phone along with
you. In the same way, computer-to-computer connections mean that as
long as you have your laptop and a connection, you're ready to go.
There are also some nifty benefits to having your calls
transmitted over the Internet. For example, some VoIP service
providers allow you to check your voicemail via your e-mail, while
others allow you to attach voice messages to your e-mails.
How VoIP Works
The current phone system relies on a reliable but largely
inefficient method for connecting calls known as circuit switching.
This technique, which has been used for over 100 years, means that
when a call is made between two people a connection is maintained in
both directions between callers for the duration of the call. This
dual directional characteristic gives the system the name circuit.
If, for example, you made a 30-minute call the circuit would be
continuously open, and thus used, between the two phones. Up until
about 1960, this meant that every call had to have an actual
dedicated wire connecting the two phones. Thus a long distance call
cost so much, because you were paying for pieces of copper wire to
be connected all the way from your phone to the destination phone,
and for that connection to remain constant throughout the call.
Today, however, your analog call is converted after leaving your
house to a digital signal, where your call can be combined with many
others on a single fiber optic cable. While this system is certainly
an improvement over the past copper wire system, it is still quite
inefficient. This inefficiency is due in part to the fact that the
telephone line can't distinguish between useful talking and unneeded
silences. For example, in a typical conversation while one person is
talking the other person is listening. Thus the current analog
system uses roughly half its space sending useless messages like
this silence. But there is also more information, even down to
pauses in speech, which under a more efficient system can be
effectively cut out rather than wasting the circuit space. This idea
of only transmitting the noisy bits of a telephone call and saving a
great deal on circuit space, is the basis of Packet-Switching, the
alternative method to circuit switching that the VoIP phone system
uses.
Packet-Switching is the same method that you use when you view a
website. For example, as you read this website, your computer is not
maintaining a constant connection to the site, but rather making
connections to send and receive information only on an as needed
basis (such as when you click on a link). Just as this system allows
the transfer of information over the Internet to work so quickly, so
also does it work in the VoIP system. While circuit switching
maintains a constant and open connection, packet switching opens
connections just long enough to send bits of data called packets
from one computer to another. This allows the network to send your
call (in packets) along the least congested and cheapest lines
available, while also keeping your computer or IP phone, free to
send and receive messages and calls with other computers. This way
of sending information, not to mention data compression, makes the
amount of information which must be transmitted for every call at
least 3-4 times less for VoIP than the exact same call in a
conventional telephone system. For this reason, VoIP is so much
cheaper than conventional calling plans.
The Future of VoIP
While most analysts believe it will be at least a decade before
companies and telephone providers make the full switch to VoIP, the
potential for the technology's use today is already quite
astounding. A report by the Forrester Research Group predicts that
by the end of 2006, nearly 5 million U.S. households will be using
VoIP phone service. With the savings and flexibility that the
technology already offers, and new advances just ahead on the
horizon, we can expect those numbers will only increase in the
future. |