Voice Over IP or VoIP is the latest buzz word on everyone's lips. VoIP literally takes your calls and places them over the internet instead of the traditional analogue phone network. As a Linux consultant it is my job to stay up to date on the latest open-source technology, as a VoIP consultant its my job to also stay up to date on the latest commercial and open-source applications available for my customers. Enter the world of Asterisk the open-source PBX by Digium, the fastest growing VoIP PBX available for EVERYONE.
The power of Asterisk is that it can run on common hardware for a fraction of the cost of a proprietary system. The one drawback link most Linux open-source applications is that if you aren't a command line guru and if you don't want to spend hours learning the complicated configuration files an Asterisk configuration can be tricky to say the least, this is where Trixbox comes to the rescue.
Trixbox, formerly known as the Asterisk@home project makes it possible for anyone to setup and configure their very own Asterisk pbx system even if they have never installed Linux before. A single CD can boot you hardware and install virtually everything you need to get started with this great application including the main feature a web configuration GUI. Not only are all the tools available to get the system up and running but a full update engine is included which will allow you to keep your system updated with the click of a button.
So what exactly do you need to get a Trixbox system installed? For the sake of this document we will assume that you need a system that can support up to 10 users. First as a general rule, it is recommended that you secure a ratio of 1:2 lines to users so for a 10 user office you need to secure five phone lines which means your system will need to be able to support ten concurrent phone lines or VoIP channels.
For a simple 10 user system, with voicemail, an IVR (automated attendant), call conferencing, call forwarding, music-on-hold, ring groups, and call queues it is recommended that you use atleast the following hardware configuration:
-AMD 64bit 3800%2B
-512MB Ram
-250g Drive
As you can see a simple Asterisk system running Trixbox which will support 10 users requires very low-end hardware. Now you need what is called a SIP provider, this is a company that will provide you with a DID (phone number), and with virtual lines for your incoming and outgoing phone calls. There are two types of VoIP providers on the market today "wholesale" and "commercial". A wholesale provider will generally give you a lot of lines 10-100 lines and ONLY charge you per minute for the calls you make.
This can be a good solution if your 10 users are on the phone all the time making outbound sales calls, the second type of provider a commercial provider, will generally charge you a monthly rate for a specific number of virtual phone lines. The decision of which type of provider to use really depends on your monthly usage, if you make a lot of long distance calls and have employees on the phone all day then a wholesale provider might offer the best overall rate for you, if your employees are only on the phone for a few hours per day then a commercial provider is perfect for you.
For more information on Trixbox visit their website at http://www.trixbox.org
Brian Carpio is a senior Solaris/Linux system architect and has worked for some of the largest companies in the world. Currently he is a freelance Linux/Solaris consultant for his own company, The Tek, LLC. IT Consulting and can be reached at info@thetek.net