VOIP, which stands for Voice Over Internet Protocol, dates back to 1995 when VocalTec released the first commercial Internet phone software. Before then there was only talk of attempting to accomplish Voice over the Internet. VOIP uses several protocols to make Voice over Internet work. In this article we will not go to deeply into how VIOP works, but we will take a look at several server options you have when setting up a VOIP server. There are also some services available online, which means almost no setup required - just open an account and start calling. But we will save those for another article.
To setup a server yourself, you need a Public Branch Exchange (PBX); the most popular option is Asterisk. All of the projects we will look at are Asterisk-based. Asterisk was created by Mark Spencer of Digium in 1999. Before Asterisk, there where other options but those where very hard to setup.
In this article, I will introduce a few full-featured Linux hosted technology VOIP options. This list might not contain your favorite or your favorite might not be listed first (the list is in no particular order). This is not an indication that I don't like that system. I choose to talk about the most popular options who often have the biggest communities, with helpful people who can help out the readers of this article if they hit a glitch with the setup that they are attempting.
As of writing this article, the Callweaver website wasn't online. I had planned to cover Callweaver as well, especially as Callweaver was one of the only PBXes to not use Asterisk. But as the website seems down for now, I will not include it. If the website comes online again, I might choose to include Callweaver at a later time.
Please note that using any of these Linux VOIP options will erase the hard drive of the computer you are installing them on. You have been warned.