IP Telephony

by Hamidur on Thursday, June 04, 2009

IP telephony refers to the system of transmitting voice over a data network such as in broadband Internet connection. In comparison to the traditional analogue phone line, as an extension to the practical Internet applications, it presents a cheaper and more accessible option to communicating with people from any part of the world. With its call sound quality that is comparable and sometimes better than that observed in analogue telephone conversations; it presents a modern and improved system for call management having total flexibility in using and locating phone numbers.

IP telephony is a general term for the technologies that use the Internet Protocol's packet switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit-switched connections of the public switched telephone network. Using the Internet, calls travel as packets of data on shared lines, avoiding the tolls of the PSTN. The challenge in IP telephony is to deliver the voice, fax, or video packets in a dependable flow to the user. Much of IP telephony focuses on that challenge.

IP telephony, broadband telephony or Voice over Internet Protocol (VoIP) applications is operated over the Internet through packets of switched network. It introduces a system of voice transmission that carry telephony signals as digital audio, which reduces data rate through speech data compression methods. It encapsulates the digital audio signals into the data packet stream over the IP. In sense, as a particular call is made, the conversation is broken down into tiny packets for faster and clearer transmission, which is then reassembled at the receiving end. One common misconception about IP telephony is that it needs to access a computer to operate. That is not the case; however, it does need a broadband Internet connection to operate.

Through Internet lines, VoIP services connect people in a number of ways:

• Computer to computer applications is perhaps the easiest way of availing VoIP services for free, no matter the distance. All it needs is a computer with a microphone, speakers, sound card and Internet connection that also runs software that supports VoIP applications.

• Computer to telephone VoIP calls, similar to computer-to-computer calls, requires a software client. It allows a person to call anyone from his computer.
• Telephone to computer calls is now made possible. Today, a number of companies are providing special numbers and calling cards, which enable phone users to call a computer user. However, the computer needs to have a vendor’s software installed but is a lot cheaper than making traditional phone-to-phone long-distance calls.

• Even telephone-to-telephone calls are possible with VoIP. By using the gateways, anyone can easily and directly contact any standard phone in the world via IP-based network.