Voice Over Internet Protocol
Voice over Internet Protocol (VoIP) is a methodology and group of technologies for the delivery of voice communications and combination sessions over Internet Protocol (IP) networks, such as the Internet. Other terms commonly accompanying with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, IP communications, and broadband phone service. VoIP is available on many smartphones, personal computers, and on Internet access devices. Calls and SMS text messages may be sent over 3G or Wi-Fi.
VoIP is an assortment of digitally encrypted voice transmissions that are carried over a network based on a single common language, or protocol in this case, the Internet Protocol TCP/IP. VoIP converts the voice signal from your telephone into a digital signal that travels over the Internet and is then converted back at the other end, so you can speak to anyone with a regular phone number. When placing a VoIP call using a phone with an adapter, you'll hear a dial tone and dial just as you always have. VoIP may also allow you to make a call directly from a computer using a conventional telephone or a microphone.
VoIP works as a peer-to-peer application, entailing handshaking and direct media exchange between two IP devices. To call someone, the user dials the telephone number, the handset translates that number into IP address format (e.g., 123.456.11.22), and the device sends encrypted data packets whose payloads contain messages conforming to a particular call-setup protocol between the two devices. They then establish a common connection for voice exchange. Their device rings, they pick up, and media packets flow in both directions.
To better understand how VoIP works, it's helpful to compare it to how conventional phone calls operate. When you place a "regular" phone call using the Public Switched Telephone Network or PSTN (also known as POTS, for Plain Old Telephone Service) it's known as a circuit-switched telephony, because it sets up a dedicated connection between two points for the duration of the call.
VoIP, on the other hand, is known as packet-switched telephony, because the voice information travels to its destination in countless individual network packets across the Internet. This type of communication presents special TCP/IP challenges because the Internet wasn't really designed for the kind of real-time communication a phone call represents. Individual packets may - and almost always do - take different paths to the same place. It's not enough to simply get VoIP packets to their destination. The packets must arrive in a fairly narrow time window and be assembled in the correct order to be intelligible to the recipient.
To improve performance, VoIP employs encoding schemes and compression technology to reduce the size of the voice packets so they can be transmitted more efficiently. Audio signals are also digitally processed in order to accentuate the voice information and suppress background noise. To conserve bandwidth, VoIP systems stop transmitting during lulls in a conversation and even generate some "comfort noise" to forestall the eerie silence that might make you think the call was disconnected. VoIP uses a number of compression standards that offer different balances between packet size and audio quality. Generally speaking, the higher the compression the more simultaneous calls you can have, but the lower voice quality will be.
Despite all of the advantages of a VoIP system, it does have its drawbacks. For instance, some VoIP services will not work during power outages and the service provider may not offer any type of back-up power solution. Many VoIP providers may not offer directory assistance or white pages listings which is essential to the small business.
The key to success with VoIP ultimately comes down to proper scheduling. The scope of a VoIP implementation can vary according to an organization's needs and desires, ranging from the relatively straightforward - using VoIP for local and long-distance calls or to communicate between a company's multiple offices - to more complex deployments like call centers.
In most cases, saving money immediately with VoIP won't require you to purchase any additional phone equipment or jettison what you already have, because devices called media gateways let conventional phone equipment (ranging from individual phones to an entire PBX) interface with your Internet connection. Taking advantage of VoIP's most cutting-edge features (like the ability to have your calls follow you as you travel) typically require specialized VoIP phones or other equipment and/or a hosted PBX service.