Saturday, January 29, 2011

Voice over IP

Voice over Internet Protocol (Voice over IP, VoIP) is one of a family of internet technologies, communication protocols, and transmission technologies for delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms frequently encountered and often used synonymously with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.

What Kind of Equipment Needed?

A broadband (high speed Internet) connection is required. This can be through a cable modem, or high speed services such as DSL or a local area network. A computer, adaptor, or specialized phone is required. Some VoIP services only work over your computer or a special VoIP phone, while other services allow you to use a traditional phone connected to a VoIP adapter.  

If you use your computer, you will need some software and an inexpensive microphone. Special VoIP phones plug directly into your broadband connection and operate largely like a traditional telephone. If you use a telephone with a VoIP adapter, you'll be able to dial just as you always have, and the service provider may also provide a dial tone.

Who can I call?

Depending upon your service, you might be limited only to other subscribers to the service, or you may be able to call anyone who has a telephone number - including local, long distance, mobile, and international numbers.

If you are calling someone who has a regular analog phone, that person does not need any special equipment to talk to you. Some VoIP services may allow you to speak with more than one person at a time.


The lower cost is the main advantage of VoIP. Since it uses a large infrastructure already built, VoIP has a wide coverage area; extending it even more is cheaper than in the case of classic landline telephony. VoIP also provides portability, allowing you to take your phone with you wherever you go and use it by connecting it to an Internet connection.

The main disadvantage of VoIP is sound quality. Since Internet networks carry a lot of data, the sound quality may drop sometimes. Also, VoIP doesn't work in the absence of electrical power, so in the event of a blackout, a VoIP phone will be inoperable.


Most VoIP operators don't support 911 calls because the calls cannot be traced, so in case of an emergency, use a regular phone to dial 911.