For more than a century now Graham Bell’s telephone has been the most popular form of interpersonal communication across the world. As more lines were laid and the technology developed, the penetration of telephone lines increased making it cheaper. Satellites added another dimension to it. Even then, the public telephones were costly, especially for ISD (international) calls. As the internet spread itself geographically as well as across sectors, voice communication too became one aspect of it. It soon developed into what is now called Internet Phone, or Internet Telephony.
Internet Telephony can be described as the routing of voice data through a network based on IP (Internet Protocol). On the internet, the voice-data is treated like any other data and is transferred through packet-switching, wherein the packets travel via different routes and get compiled at the user end. This is unlike public telephone lines where dedicated channel of communication is created for voice transfer. This results in undue waste of bandwidth resources. The voice-data gets transferred via a special extension of the Internet Protocol, called Voice-over IP. As VOIP rides on IP, internet phone may be used on any network using IP. VOIP does not cost anything over and above normal internet usage charges, and hence may be viewed as ‘free’.
There are a number of services that have sprung up to facilitate this type of "free" VoIP call. Examples are Google Talk, Skype, TheGlobe, or the ubiquitous Yahoo Messenger. There are several advantages to internet phone: it is cheap; calls may be routed anywhere in the world with access to internet; it integrates with other internet options like video phone, text messaging, file transfer, etc. With increasing internet density, VoIP is increasingly becoming popular as a mode of voice communication. Some options even allow calls to be taken on a public network telephone, for a token charge, making it even more useful (thus, even someone not having a computer may be contacted).
This section of webdirectory provides you with useful links to many VoIP solutions, relevant hardware and accessories, etc.