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Written by Gert-Jan de Boer,
Sunday, 21 May 2006
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Is your company thinking about implementing Voice over IP? Looking at all the new players in the communication market? Checking out vendors like Avaya, Cisco, Nortel, etc. ? Perhaps there's an open source vendor which will suit your needs. There are several Open Source PBX (Private Branch eXchange) systems, from which Asterisk is the most well-known. This article will tell you something what Asterisk does, how it works and what it costs. In a couple of follow-up articles I will explain configuration and more advanced caveats.
Asterisk is an PBX developed by a company called Digium. More important: Asterisk is developed in an Open Source business model. This means that the code is open and that anyone can look at the source code and can change it. Everyone can help to improve Asterisk, and this model made Asterisk so complete as it is right now. Asterisk installs on Linux, BSD and Mac OS X and can interface with hardware cards from Digium or standard CAPI ISDN cards. This will provide your link to the outside world. Also Asterisk can interface with SIP (Session Initiated Protocol) or IAX (Inter-Asterisk eXchange) trunks. This way you can interconnect Asterisk to a SIP provider like VoipBuster or link it to another VoIP PBX thru a SIP trunk.
Now for the software, what can it really do? Asterisk provides SIP services, so you can connect SIP compatible IP phones. It provides Voicemail, IVR (Interactive Voice Response), Dial Plans, Queueing for receptionists or callcenters. For most of these functions (like voicemail and IVR) you need to buy another solution from the same vendor you chose for your VoIP PBX, but in Asterisk this is all built-in.
But what are the down-sides of Asterisk, one might ask. Well, when you buy a complete solution from a vendor mostly the configuration is very easy after initial installation (e.g. Cisco CCMAdmin.) Second: Asterisk has lots of configuration files and you need to be comfortable in the configuration terminology. To solve these problems several companies provide support on Asterisk (e.g. Digium itself with Asterisk Business or Astrium in the Netherlands.)
In the next article I will explain the configuration of Asterisk and we will setup a base system using an SIP provider. No hardware needed! |
