is an acronym used for voice over Internet
It is a technology that enables people to use the Internet as
the transmission medium for telephone calls. It can turn a standard Internet
connection into a way to place free phone calls. It is a revolutionary
technology that has the potential to completely rework the world's phone
system. It is also called IP Telephony, Digital Phone and Internet
There are three different ways by which VOIP calling
can be done.
- ATA - The simplest and most common way is through
the use of a device called an ATA (analog telephone adaptor). The ATA
allows to connect a standard phone to computer or Internet connection
for use with VoIP.
- IP Phones - These specialized phones look just like
normal phones with a handset, cradle and buttons.
- Computer-to-computer - This is certainly the
easiest way to use VoIP.
Working of VOIP
VOIP converts the voice signal from the telephone
into a digital signal that travels over the Internet. This digital signal
again gets converted to voice signal at the other end.
- You pick up the receiver, which sends a signal to the ATA.
- The ATA receives the signal and sends a dial tone. This lets you know
that you have a connection to the Internet.
- You dial the phone number of the party you wish to talk to. The tones
are converted by the ATA into digital data and temporarily stored.
- The phone number data is sent in the form of a request to your VoIP
company's call processor.
- The call processor checks it to ensure that it is in a valid format.
- The call processor determines to whom to map the phone number. In
mapping, the phone number is translated to an IP address.
- The soft switch connects the two devices on either end of the call.
- On the other end, a signal is sent to your friend's ATA, telling it
to ask the connected phone to ring.
- Your friend then picks up the phone at the other end.
Advantages of VOIP
- It is digital and offer features and services that are not available
with a traditional phone.
- One need not maintain and pay the additional cost for a phone line.
- Talk for maximum time period with much reduced cost.
- Talk with many people at the same time without any additional cost.
- Call center agents using VoIP phones can easily work from anywhere
with a good Internet
Disadvantages of VOIP
- Some VOIP services don't work during power outages and the service
provider may not offer backup power.
- Not all VOIP services connect directly to emergency services through
- VoIP providers may or may not offer directory assistance/white page
- Another issue associated with VOIP is having a phone system dependant
on individual PCs of varying specifications and power. A call can be
affected by processor drain.
- VOIP is susceptible to worms, viruses and hacking
- The nature of IP makes it difficult to geographically locate network
users. Emergency calls, therefore, can not easily be routed to a nearby
call center, and are impossible on some VOIP systems