Overview of VoIP <ul><li>Voice over Internet Protocol (VoIP) is an emerging set of applications which allows you to make telephone calls over the Internet, that is by using some of the free VoIP software available to make Internet phone calls, you are bypassing the phone company (and its charges) entirely. </li></ul><ul><li>VoIP was originally developed to provide voice communication between computer users in different locations. Although it still has this application, it has been further developed into a telephone network in its own right </li></ul>Background Overview of VoIP It all started back in 1995 when Israeli computer enthusiasts made the first computer to computer voice connection. In the same year this technology was developed into a software package called Internet Phone Software. All that was needed to talk to another computer user was a modem, sound card, speakers, and a microphone
VoIP services convert your voice into a digital signal that travels over the Internet This is done by 'sampling' your voice -- dividing the analog sound signal into discrete steps that can be assigned a number value. Once your voice is digitized, the data can be compressed This compressed digital data is split up into 'packets' of about 1500 bytes that can be transferred over the Internet. As well as the voice data, the packets contain information about their origin, their destination, and a timestamp that allows them to be reconstructed in the correct order. Once they arrive at their destination, they are reassembled and converted from digital back into analog so that the receiving party can hear your voice. If you are calling a regular phone number, the signal is converted to a regular telephone signal before it reaches the destination. VoIP can allow you to make a call directly from a computer, a special VoIP phone, or a traditional phone connected to a special adapter .(As shown in the slide before) In order for voice data to be transmitted without noticeable delays, a high speed broadband Internet connection is necessary
Advantages of VoIP VoIP has lots of advantages over a regular phone service. However, like any emerging technology, there are still a few kinks in the system. However, as standards are developed it becomes more reliable and achieves greater acceptance. VoIP will eventually replace traditional phone service – in fact, phone companies are already taking advantage of the technology to offer cheaper long distance rates. One of the main advantages of VoIP is the low cost Another advantage of VoIP is portability Call forwarding, call waiting, voicemail, caller ID and three-way calling
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. (charges depends on the VoIP providers) portability You can make and receive phone calls wherever there is a broadband connection simply by signing in to your VoIP account. This makes VoIP as convenient as e-mail – if you are traveling, simply pack a headset or Internet phone and you can talk to your family or business associates for almost nothing. Phone-to-phone VoIP is also portable .
Disadvantages of VoIP Continuous service during a power outage emergency calls sound quality and reliability 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 and they are listed below
power outage During a blackout a regular phone is kept in service by the current supplied through the phone line. This is not possible with Internet phones, so when the power goes out, there is no VoIP phone service. One solution to this problem is to use battery backups or power generators to provide electricity. emergency 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. There is an emerging standard called e911, however, which attempts to address this issue.
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. But this is more of a problem in VoIP because of the real-time nature of VoIP In order to make voice connections with the least amount of delay, some packets may have to be dropped if they don't arrive in time