As communication technology is rapidly advancing, VoIP softphone is becoming more popular than traditional telecommunication mode; and people from all over the world can communicate with their friends and relatives through VoIP softphone. A softphone is computer software, which when installed on any general purpose computer allows the user to make phone calls using internet connection.
The user can call from computer to computer or from computer to phone any time. This software uses VoIP technology to transfer audio as well as video data over the internet.
There are many VoIP softphones which provide free calls from computer to computer where as very few softphones provide calling from computer to phone and phone to computer. Generally this software is designed like a traditional phone which shows replica of phone image with buttons and display screen to view dialed number. This software normally uses USB Phone or headset connected to the sound card of the computer to enable talking. Softphone has standard telephone features such as mute, hold, transfer, flash and dual tone multi frequency signaling. Some softphones also provide additional features such as video, messaging and user online availability indication. This software comes with variety of audio codec such as G.711 and G.729, which are used for converting human sound to internet packet so that it can be transmitted over internet.
Working VoIP Softphone:
When a person speaks through microphone or speaker, the voice which is in analog form will be converted to digital format through the software and then it will be transferred to internet. The receiver’s computer at the other end will convert this digital data back into analog data so he can hear that sound.
In order to converse, both ends should have same protocol for communication, and at least one similar audio protocol. SIP (Session Initiation Protocol) is widely used by majority of softphones for communication over internet, as it is a standardized Protocol by internet standards IETF (Internet Engineering Task Force).
Requirements for Softphone:
Here are some basic requirements to use VoIP Softphone service on a home computer.
• Modern Computer
• Headphone
• Headset or microphone with speaker or USB Phone
• IP PBX or VoIP service provider
• High speed internet
Open source VoIP Softphone: As softphone is commonly used on Notebook or PC for voice communication without a dedicated telephone device; there are number of open source VoIP softphones available which can be deployed on one or many computers or devices. Some of the open source software are:
• QuteCom: It is designed by French VoIP provider Wengo, which integrates instant messaging, voice and video calls. It works on Windows, Linux and Mac OSX.
• SIP Communicator: It is developed in Java which initiates instant messaging and cross-platform VoIP. It uses SIP for voice communication.
• SFLPhone: It is designed by Canadian Linux Company Savoir-Faire Linux, which is compatible softphone for Linux. It offers features such as call recording, hold, call transfer and unlimited calling.
• Empathy: It is a unified communication client which supports audio, video, text file which could be transferred over various protocols.
• Ekiga: It is a video conferencing softphone for GNOME desktop which was known as GnomeMeeting earlier.