This article demonstrates how easy it is to roll your own PBX in about an hour or two. Provided that the instructions herein are followed carefully, you too should be able to set up your very own switchboard/PBX system and all for the cost of the target hardware of your choice.
What is a PBX and why set one up?
A PBX or “Private Branch Exchange” is like a miniature phone company/switch in your own office/house. The PBX is responsible for making sure calls are routed properly. Situation: when Joe wants to dial Suzy in the office down the hall or downstairs in the TV room, he just picks up the phone in his room/office and dials a local extension just a few digits long. If he wants to call someone across town or around the world, he dials an “outside line” prefix (usually a 9) plus the desired number and the PBX routes his call to the PSTN (Public Switched Telephone Network) just like any other dialed call. Also, if Joe has four teenaged kids, instead of answering their calls and acting as the house receptionist, he can just setup a menu that allows callers to dial the person they want and then needs not be disturbed.
Most people are familiar with PBXs because they’ve used them in an office environment, but what if you wanted to use one in your house? Enter Asterisk.
The beauty of Asterisk (Asterisk.org) is that it is free and offers all this functionality right out of the box. Asterisk is a software implementation of a hardware PBX and can run on a variety of hardware platforms. The features and benefits of owning an Asterisk PBX are numerous, and seemingly only limited by the imagination of the person who sets up and uses an Asterisk PBX. Listed on the project page are just some of the many features that can be implemented. I encourage anyone to explore these features as it will give you some idea for setting up your system in a way that makes it more than worth your while.
Prepare for setting up your PBX for VoIP gsm termination
There are many ways of setting up an Asterisk PBX, with some being easier than others. The easiest manner in which to set up a fully functional Asterisk PBX is to download and install a precompiled/tuned distribution such as Trixbox, PBX in a flash, Asterisk NOW, etc. Just take your pick of those. These are great if you don’t care to learn about how your PBX operates or need to do a mindless “click and drool” install. The problem with precompiled asterisk distributions is, while they are simple, they are not as flexible and extensible as a home-brewed Asterisk installation from the source code. When you install one of these “distros”, it is quite often that important decisions are already made for you, and you must work within the framework of the distribution to keep the box “happy”. When you roll your own Asterisk from the sources, you get more say in what goes into the build and how it is customized/extended at the expense of a slightly more complicated planning and installation process. However, it’s not as hard as you might think and it’s quite worth it in the end to “roll your own”.
Asterisk installed from the source code enables you to pick your choice of underlying OS (Debian, Ubuntu, Fedora, Mandrake, SuSE, etc) and also fine tune the installation for your OS environment and your hardware for best possible performance. In this article I will cover the steps needed to install Asterisk for the Ubuntu Linux operating system. This article assumes you know how to do a minimal command line only base system install of Ubuntu Linux. You certainly don’t want to run a GUI on your Asterisk box as it would consume unnecessary resources.