Voice-over-IP Overview
Voice-over-IP (VoIP) implementations enables users to carry voice traffic (for example, telephone calls and faxes) over an IP network.
There are 3 main causes for the evolution of the Voice over IP market:
- Low cost phone calls
- Add-on services and unified messaging
- Merging of data/voice infrastructures
A VoIP system consists of a number of different
components: Gateway/Media Gateway, Gatekeeper, Call agent, Media Gateway
Controller, Signaling Gateway and a Call manager
VoIP is a revolutionary technology that has the potential to completely rework the world's phone systems.
The interesting thing
about VoIP is that there is not just one way to place a call. There are three
different "flavors" of VoIP service in common use today:
ATA
The
simplest and most common way is through the use of a device called an ATA
(analog telephone adaptor). The ATA allows you to connect a standard phone to
your computer or your
Internet connection for use with VoIP. The ATA is an analog-to-digital
converter. It takes the analog signal from your traditional phone and converts
it into digital data for transmission over the Internet.
IP Phones
These
specialized phones look just like normal phones with a handset, cradle and
buttons. But instead of having the standard RJ-11 phone connectors, IP phones
have an RJ-45 Ethernet connector.
IP phones connect directly to your router and have
all the hardware and software necessary right onboard to handle the IP call.
Computer-to-computer
This
is certainly the easiest way to use VoIP. You don't even have to pay for
long-distance calls. There are several companies offering free or very low-cost
software that you can use for this type of VoIP. All you need is the software,
a microphone, speaker a good sound card and an
Internet connection, preferably a fast one like you would get through a cable or DSL Modem
Another
alternative is the softphone. A softphone is client software that loads the
VoIP service onto your desktop or laptop. As long as you have a
headset/microphone, you can place calls from your laptop anywhere in the
broadband-connected world.
Using VoIP
By routing thousands of
phone calls through a circuit switch and into an IP gateway, they can seriously
reduce the bandwidth they're using for the long haul. Once the call is received
by a gateway on the other side of the call, it's decompressed, reassembled and
routed to a local circuit switch.
With VoIP, you can make a
call from anywhere you have broadband connectivity
Features:
· Caller ID
·
Call waiting
·
Call transfer
·
Repeat dial
·
Return call
·
Three-way calling
Advantages of Using VoIP
VoIP technology uses the
Internet's packet-switching capabilities to provide phone service. VoIP has
several advantages over circuit switching. For example, packet switching allows
several telephone calls to occupy the amount of space occupied by only one in a
circuit-switched network.
Ref:
retrieved from http://computer.howstuffworks.com/ip-telephony7.htm - accessed on 26/03/2014
