Voice over internet protocol (VoIP) is actually a methodology and technologies for delivering voice and multimedia over the internet protocol which is called the IP. Other terms with VoIP are IP telephony, Voice over broadband, broadband telephony, IP communications.
The technology is steadily growing and is expected to show a 28% growth in between 2016 and 2020, while copper cables and replaced by high-speed fiber-optic lines. The whole VoIP service market is expected to reach whooping $140 billion by 2012 (more market report details here). Meanwhile, let get down to the technical side of the technology and see how it works. The term internet telephony specifically refers to the communication services over the public internet. The process and principles involved in VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of analog voice signals and encoding.
VoIP systems employ session control and signaling protocols to control the signaling protocol setup and tear down of calls. Each providers of voice over IP services mirrored the architecture of legacy phone communication. Skype is an example for VoIP where users need to register to make a phone call for free from PC to PC or mobile to mobile or the mixture of both. The working of a VoIP is similar to a legacy phone call but this uses public internet to make calls, without internet VoIP will not function.
VoIP technologies enabled multiple call center platforms processing all kind of phone calls and ranging from airtickets bookings to complicated tech support. High speed of those call centers allowing larger businesses to outsource part of their departments to regions with lower human work costs and thus increasing revenues of the companies.
A telephone connected to a land line has a direct relationship between a telephone number and a physical location maintained by the phone company and available to emergency responders via national emergency service centers in the form of subscriber lists. When an emergency call is received by a call center the location is auto detected from its data collection base and displayed on the console.
Many business phone systems like some ecommerce marketing agency for example have VoIP facilities also to use it for calling along with legacy phone type system. Various codecs exist that optimize the media stream based on application requirements and network bandwidth. There are many types of protocols in VoIP like H.323,Media gateway control protocol, Session initiation protocol, h.248, real time transport protocol, real time transport control protocol, secure real time transport protocol, session description protocol, inter astericsk exchange, jingle XMPP, Skype protocol, TeamSpeak.
Caller ID support among VoIP providers varies but is provided by the majority of VOIP providers. Many services allow callers to configure callerID information, thus permitting spoofing attacks. Business grade VoIP equipment and software often makes it easy to modify caller ID information providing flexibility. Some VoIP service providers implement services to route calls to other telephone network services of the subscriber such as a cellular phone in the event that the customer’s network device is inaccessible to terminate the call. Telephones for traditional residential analog service are usually connected directly to telephone company phone lines which provide direct current to power the most basic analog handsets.