VoIP Overview

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