Tip of the Trade: Asterisk
January 2, 2007
The life of the network or system administrator is rarely a peaceful one. There you are, minding your own business, everything is working, users are hardly complaining, and along comes the boss with a new job for you.
"We're going to do voice over IP and save meelyuns of dollars on our phone bills!" says the boss. You sit frozen in shock because you know this means your comfortable existence is about to be altered.
The boss continues. "And we're going to do it for free with Asterisk! Hurrah for free software! Make it so, and I'll check back with you in a couple of hours!"
Well now, you know this is going to take longer than a couple of hours, but there's no escape, so you might as well get started. But where to start? That's the question today's Tip is going to answer. VoIP is complex, requiring knowledge of both computer networking and telephony. Fortunately, vast quantities of great information are just a few mouse clicks away. Here are some choice resources to get you off on the right foot:
Asterisk is a telephony powerhouse, and comes in both free-of-cost and commercial versions. The commercial edition is at Digium.com. Digium is the sponsor of Asterisk, and makes telephony interface hardware. If you must get up and running quickly, opt for the commercial version. It comes with nice management tools and good technical support. The free-of-cost edition is great for production systems, but you better be good at figuring things out with the help of Wikis, mailing lists, books and forums.
A couple of tips to get you started with the least aggravation:
It is best to set up a three-PC test lab before trying to run a production Asterisk server. Use one for the server, and the other two for clients. This little setup will let enable you to test just about everything you can do with an Asterisk server.
On production systems, don't skimp on the hardware. Linux users are accustomed to scavenging tired old systems and finding useful jobs for them, but processing VoIP calls can be CPU-intensive, so don't try it for Asterisk. Asterisk is designed to perform PBX functions in software because x86 hardware is much less expensive than specialized telephony hardware so you're still saving money.