Setting Up An IP PBX in Your Company (or Home)

Ok, I’ve made some tall promises before. NOW I’m telling you that I can get you an IP PBX with email-integrated voicemail, auto attendants, text to speech, call queuing, and more on my plan: Never pay for software? That’s right. Read on intrepid dialer.

Anyone that knows me or my history knows that I have done PC-based PBX work for the majority of my professional life. It’s near and dear to my heart. I have extremely high standards of what is a “good” phone system because I’ve competed against, integrated with, replaced, and otherwise beat up on old iron PBXs with the best of them. The flexibility that is offered by switching those phone calls through a more intelligent computer just can’t be beat. I sold these systems in major call centers, US government sites, and small companies. The down side was they were horrifyingly expensive to buy, setup, and maintain. They also required a lot of skill to really make them perform, which generally meant large sums of money to a vendor.

I even run a phone system on my home phone. While it may seem excessive, ask yourself if it would be worth $100 to never speak to a telemarketer again. You see, the predictive dialers they use hear a recorded message and assume that it’s an answering machine, so the call never even gets forwarded to an agent. If someone does hear my message they hear “Thank you for calling the Biven residence, if this is an unsolicited telemarketer hang up now. All other callers press 1 to continue.” Pressing one simply rings my home phone.

“Great, let’s do it” you say? After all, you have a spare PC sitting around (I know because I have three right now). Pretty sure you also have a spare modem or two? Well too bad. These things require specialty telephony (pronounce it right, please) hardware to be able to bring calls in from the Public Switch Telephone Network (PSTN). Thankfully for us the cards to set up a small home or corporate system are cheap. You can get them for $26 US each from DigitNetworks at this link. If you don’t like them or you’re the ebay type click that link and get your model numbers. For more serious applications requiring digital trunks (T1s or PRIs in the US) or simply a need for higher density analog trunking there are other boards. We won’t get into that here.

So let’s cut to the chase. The software package is called “Asterisk” and is produced by a company by the name of Digium. If you were listening earlier you got the idea I’ve been around this block. I can tell you without a doubt that Digium has done an outstanding job with this product. While it lacks some of the bells and whistles that some of it’s competitors it has everything that counts, not the least of which is stability. I have been running various versions of Asterisk for over a year and have not had a single crash.

If you’ve done computer support you know how crabby people get when their email goes down. Now, email is a great tool that people rely on. Dial tone, however, is a God given right. Take that away for five minutes and someone will be down in your office screaming. Or crying, depending on the day. So before you go running off to the boss to tell him how you can take over the telephones think that through.

Asterisk is configured using a series of well designed text files. This beats the pants off of some of these huge, proprietary graphical programming tools that some vendors offer for obvious reasons including the ability to program the system over ssh. The sound files for the system’s auto attendants and IVRs are simple 8kHz .wav files. Everything is very standard, which is perfect. Disappointing, to a degree, for us is that it is really designed to work with Linux. Some of the hardware drivers for FreeBSD are still in beta, which we just can’t have. Oh well, you can’t have it all.

There are some wonderful add-ons for Asterisk now as well. One of the better ones is called the Asterisk Management Portal, or AMP for short. AMP allows you to configure your Asterisk system from an easy to use web interface. Upload prompt files, create phones and trunks, routing plans, queue creation, etc. It takes some of the power away but it does an excellent job of allowing someone with little to no experience to set it up.

Many operators and other users like to get a graphical view of who’s on the phone. Some use the enormous and expensive sidecars to their desk phone, the lucky ones have some sort of PC based application. Well, the Asterisk solution is the Flash Operator Panel. It will show you who’s on the phone, who with, what the status of your queues is, as well as allow you to transfer calls.

There are simply too many add-ons to list them all. To find more take a look at http://www.voip-info.org/ . This site also a treasure trove of information on everything SIP and Asterisk. If you decide to go with a self-built system you can find a lot of excellent information there. Compiling from source yourself, getting the right drivers, bolting on the proper add-ons, etc etc can take quite a while. Odds are you will screw it up a few times before you get it right.

”Wait a minute, did you just say *IF* I decide to build it myself?” Yes. There is a wonderful open source project called, simply, Asterisk@Home. They have a marvelous iso image that will install a base Linux system, compile Asterisk from scratch, install some excellent add-ons including the two discussed earlier, and in general take care of you better than your mother did. It’s literally drop in CD, turn on computer, wait, log in to AMP and setup up your phones. I cannot recommend it enough. Do this first!

I’m not going to go into further detail on configuration, read the Asterisk@Home Handbook for the step-by-step guide. That’s what it’s there for. Good luck and happy dialing.