Voice Over Internet Protocol (“VOIP”) is a technology that allows voice and video to be sent over a computer network. The most common use of VOIP today is to make and receive telephone calls over the internet.
VOIP telephones are specially designed telephones that plug in to a computer network instead of a traditional telephone jack and which can make and receive telephone calls using a VOIP Switch. In order for a VOIP telephone to make or receive phone calls, the telephone must be programmed to connect to a VOIP switch. There are a number of companies that manufacture VOIP telephones, including Aastra, Polycom, Grandstream, Cisco, Yealink, Snom, and others.
An Analog Terminal Adaptor (“ATA”) (also known as an FXS Gateway) is a device that allows you to connect a conventional telephone with a VOIP system. An ATA typically consists of a box with one or more traditional telephone jacks and a single network connector. You can plug one traditional phone into each jack, and the ATA will allow that phone to make and receive calls. Like VOIP telephones, an ATA must be programmed to connect to a VOIP switch in order to make or receive calls. ATAs are manufactured by Obihai Technologies, Sangoma, Cisco, Grandstream, and others.
An FXO Gateway is a device that allows you to connect a conventional telephone line from a telephone company to a VOIP system. Like VOIP telephones and ATAs, the FXO Gateway must be programmed to connect to a VOIP Switch in order to be used to make or receive phone calls. FXO Gateways are made by Obihai Technologies, Sangoma, Cisco, Grandstream, and others. These companies also make PRI and BRI Gateways which can be used to connect to digital lines from a telephone company.
a VOIP Switch is a device (such as a computer) that runs a computer program that is designed to connect to VOIP telephones and ATAs and route calls to and from them. In addition to communicating with VOIP telephones and ATAs, a VOIP switch can also communicate with other VOIP switches, so that calls can be passed from one VOIP switch to another until the call reaches its destination.
A VOIP Service Provider is a company that operates a VOIP Switch that is also connected to and can route calls to and from traditional telephone lines. Typically, VOIP Service Providers will send outgoing calls to traditional telephone numbers for a fee, and also will offer the option of allowing you to purchase a telephone number which, when someone calls that number from a traditional telephone, the VOIP Service Provider will then route to your VOIP telephones or your VOIP Switch for a fee.
Asterisk is a computer program that can be configured to act as a VOIP switch. Asterisk can be configured to operate like a telephone company central office or like a business PBX. Many VOIP Service Providers use Asterisk as their VOIP Switch, and Asterisk can also be configured to operate as a PBX for a business or institution. Asterisk is open-source software, which means that it is available for anyone to use at no cost. Asterisk was originally written by Mark Spencer, and is now maintained and developed primarily by the company that Mr. Spencer founded called Digium, Inc. Asterisk is designed to run on a computer running Linux. It is configured using a set of text files ending in .conf that are typically located in the /etc/asterisk folder.
A Router is a computer networking device that connects a Local Area Network (“LAN”) used in a business or institution to another network, such as the internet. The choice of router when using VOIP is very important. Because VOIP traffic is usually sent over the very same internet connection as other data traffic, it is important to ensure that your router give preference to VOIP traffic over other data traffic. Otherwise, you may experience call quality issues, including choppy audio, and you may experience failed outgoing calls or missed incoming calls. A router is also a very important security device, because a router can be configured to prevent unauthorized persons from accessing your VOIP telephones and your VOIP Switch.
Wifi is a means of accessing a computer network without physically connecting wires to it. Wifi is important to VOIP because it can allow VOIP telephones to be located in areas where wires are not available. However, Wifi access points can also cause interference with some cable/dsl modems and even some routers. While such interference may not be noticeable when using a data connection to surf the web or check email, Wifi transmitters can cause serious problems with VOIP traffic, which is much more time sensitive. As a result, it is wise to always keep your Wifi transmitter several feet away from any other networking equipment, including any switches, routers, or modems.