How Does VOIP Work

How Does VoIP Work? Internet telephony refers to communications services—voice, facsimile, and/or voice-messaging applications—that are transported via the Internet, rather than the public switched telephone network (PSTN). The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is then reversed at the receiving end — switching the digital format back to analog so the telephone call goes through as normal.

More information on How Does VoIP Work? Internet protocol calls (VoIP) originate on any broadband line: coaxial cable, DSL, wireless or even satellite. The call is routed to the VoIP Company, where a computer converts the sound into data packets – similar to the packets used to transfer Internet data such as email. Sending data by packets is far more efficient as it enables the same line to handle more information simultaneously. These data packets are sent through any of the Internet’s multiple networks to a recipient of the call. The caller can receive the call via a wireless provider, a broadband provider, or a local phone carrier.

Let’s see some more information on how does VoIP work?

Unlike the conventional phone system, which is a circuit-switched network, VoIP sends calls over the Internet, a packet-switched network. It first converts the voice traffic into data packets. These packets are then routed over the Internet in the same way as other data, reassembled at the point of arrival, and then converted back to voice.

How Does VOIP Work? In order to understand VOIP it is essential to have a complete understanding of what the difference between circuit switching and packet switching. A normal telephone uses circuit switching for phone calls, which involves routing of your call through the switch at your local carrier to the person you is calling. The connection of two points in both directions is known as circuit. Packet switching on the other hand is more efficient in transmitting data since small amount of data, which is called a packet, is sent from one system to another. Data networks do not use circuit switching because there is huge data loss.

Because VOIP uses packet switching it possesses several advantages over circuit switching. The key difference between packet switching and circuit switching is that packet switching allows numerous telephone calls to inhabit the space occupied by only one in a circuit-switched network. For Example: A 20 minute phone call under PSTN would use 20 full minutes of transmission time that too at a cost of 128 Kbps. The same thing if done using VOIP, may have taken only 5 to 7 minutes of transmission time that too at a cost of 64 Kbps. The space, which is saved under VOIP, can be effectively utilized in making three or four more calls instead of making a single call under the conventional system based on this simple estimate. Data compression further reduces the size of each call, which makes calling under VOIP much cheaper.

VOIP uses two main protocols to define ways for devices to join to each other which also includes specifications for audio codec which stands for coder-decoder, used to convert an audio signal into a compressed digital form for transmission and back into an uncompressed audio signal for replay.

H.323 is the first protocol used in VOIP. It is also a standard created by the International Telecommunications Union (ITU). H.323 provides specifications for real-time, interactive videoconferencing, data sharing and audio applications such as IP telephony. Session Initiation Protocol (SIP) is an alternative to H.323 developed specifically for IP telephony. SIP is smaller and more efficient than H.323, and it takes advantage of existing protocols to handle certain parts of the process.

The four different methods of communication, which VOIP offers, are computer-to-computer, computer-to-telephone, telephone-to-computer, or telephone-to-telephone.