VoIP (Voice Over Internet Protocol) allows users to make phone calls over the internet instead of traditional phone lines. It uses CODECs to compress audio samples into small packets that are transmitted over IP networks and decompressed on the other end. Popular VoIP services like Skype allow free video and voice calls between users. While VoIP has advantages like low cost international calls, it also has disadvantages like unreliable sound quality and inability to make emergency 911 calls.

1. VoIP: Voice Over Internet ProtocolBy Emma-Marie Whittenham

2. Introduction to VoIPThe major development of VoIP’s started in 2004 when it was introduced to the mass market of Internet users and broadband users which subscribers can place and receive and make telephone communications in the same manner as you would use a switch telephone network.VoIP can be connected via Ethernet or Wi-Fi, an analogue adapter device, cable modems and can recently be used with smart phones.

3. Web applications such as MSN Messenger, Skype, AOL Messenger, AIM, Apple Chat use this protocol to connect with other users for voice and video connection over the internet. Most of these applications are free, but can be upgraded for a subscription fee.VoIP is useful because it is a great way to stay in contact with friends and family using video and voice chat over the internet.

4. Recently it has been brought to Xbox Live and Playstation (PSN) for chat whilst playing a game.Games such as Call Of Duty, including many other first person shooting games use this facility so that the game is more realistic and you are able to connect with other players who are playing the same game.

5. Businesses also find it useful for meetings over the internet, talking to other colleagues and other companies.It is a great way to keep in contact with other businesses, do interviews and even just contact other members of a company without moving from your seat and even being able to speak to them face to face via the a webcam.

6. Of course, there is much more required in order to make VoIP work. When recording the sound samples, the computer might compress those sounds so that they require less space and will certainly record only a limited frequency range. There are a number of ways to compress audio, the algorithm for which is referred to as a "compressor/de-compressor", or simply CODEC. Many CODECs exist for a variety of applications (e.g., movies and sound recordings) and, for VoIP, the CODECs are optimized for compressing voice, which significantly reduce the bandwidth used compared to an uncompressed audio stream.How it works…Many people have used a computer and a microphone to record a human voice or other sounds. The process involves sampling the sound that is heard by the computer at a very high rate (at least 8,000 times per second or more) and storing those "samples" in memory or in a file on the computer. Each sample of sound is just a very tiny bit of the person's voice or other sound recorded by the computer. The computer has the wherewithal to take all of those samples and play them, so that the listener can hear what was recorded. VoIP is based on the same idea, but the difference is that the audio samples are not stored locally. Instead, they are sent over the IP network to another computer and played there.Once the sound is recorded by the computer and compressed into very small samples, the samples are collected together into larger chunks and placed into data packets for transmission over the IP network. This process is referred to packetization. Generally, a single IP packet will contain 10 or more milliseconds of audio, with 20 or 30 milliseconds being most common.

8. Advantages:Low cost - One of the main advantages of VoIP is the low cost. If you have a fast Internet connection (DSL or cable) you can make PC-to-PC phone calls anywhere in the world for free. If you wish to make a PC-to-phone connection, however, there's usually a charge for this but probably much cheaper than your regular phone service. Limited Emergency Calls - Another major concern involves emergency 911 calls. Traditional phone equipment can trace your location. Emergency calls are diverted to the nearest call center where the operator can see your location in case you can't talk. With VoIP, however, their is currently no way to determine where your Internet phone call is originating from, so most VoIP services cannot be used for emergency calls. Sound Quality And Reliability - Some VoIP providers have problems with sound quality and reliability. Data sent across the Internet usually arrives at its destination in a scrambled order. This is not a problem for e-mail or documents because the data can be reassembled in the correct order once it has all arrived. Disadvantages:With all this going for it, it's a wonder that anybody still uses regular phone services. However, there are a few disadvantages to VoIP. Continuous service during a power outage and emergency calls are two of the biggest problems.

9. VoIP has proved itself to be extremely useful and revolutionary over the internet world. Its useful for families, businesses, gamers and mobile users to keep in contact with other people and has also started growing for the dating world. Soon everyone will be able to experience the usage of VoIP with no problems as the services and providers are making it easier for people to connect.Many people already use VoIP without even realising its full potential. Young people are the main users of VoIP protocols as the new generation of young people are using social networking sites to connect to friends and to socialise.