Would You Like A Professional Telephone System For Your Office Or Home For Free?

Skeptic or not, I can anticipate some of the questions that you're thinking.

"What's the catch?"

Well the software really can be downloaded and used for free. It's called Asterisk. It's available under the GNU Public License. It has developed its own following and even has an annual convention. Commercial systems have also been developed around Asterisk.

Asterisk was originally developed by Mark Spencer, who works at a company called Digium. But many others have now contributed to Asterisk. That's the beauty of open-source software. Running Asterisk gives you the capabilities of a private branch exchange (PBX). Some of the features include voicemailboxes, call forwarding, call screening, call blocking, automatic call distribution (ACD), music-on-hold, complete incoming and outgoing call-logging and reporting, wake-up calls, and interactive voice response (IVR). You know IVR right? The dreaded press 1 if you're impatient ... over and over. It allows you to attach telephones that can call each other extension to extension. Each extension is private and the calls you make from one to another are private. You can hold, transfer, and make conference calls with ease.

"What does Asterisk run on?"

It runs on a PC. The operating system it runs under can be Linux (its first and probably preferred system), or some other flavor of Unix, or even Windows now I believe. But before you ask. Linux is also available free under the GNU Public License. And many people run Asterisk and Linux on an old cast off PC that they bought for $50 on eBay (at least for small systems). Although like any program, the bigger and snappier your PC is, the better it runs. And the more users your system can support.

"How do I make calls from one extension to another?"

You can run a software program on a PC that communicates with the server and functions like an extension on a PBX. The communications between your PC and Asterisk use industry standard Voice Over Internet Protocols (VoIP). Actually there are different protocols available. You can configure which one Asterisk will use for most of the available devices it can communicate with. Session Initial Protocol (SIP) is a widely-used and popular one. You need a PC with a sound card. And you need either microphone and speakers. Or instead of speakers you can use a headset. Most of these programs put a picture of a phone on the screen and you click on the buttons to dial. If there is another PC on your network running a similar program, you call it just like you would on a real PBX. The program digitizes your voice and sends it over your computer network using VoIP.

"Only extension to extension?"

No, of course not. But remember the "catch" that you asked about? Well I never answered that. There may be a number of "catches" with Asterisk and this is the first.

To make calls outside your private phone system you need some sort of connection to the public switched telephone network (PSTN). PSTN that's the existing phone network as you know it, or remember it. Sometimes people also call this plain ol' telephone service or POTS. There are two primary ways to do this. I'll cover the first now and the second later.

Have you seen all the ads on TV lately for VoIP companies? With a VoIP phone you can connect to one of these companies and make and receive phone calls. The VoIP phone digitizes your voice and sends it over the Internet to the VoIP company. The VoIP company has PSTN connections to allow you to make your call to real telephone numbers. And the reverse is also true. The VoIP company has real telephone numbers they assign to receive calls that will automatically go through their system and be routed over the Internet to your VoIP phone. Well Asterisk can be a VoIP phone to those companies. Many of the companies already know about Asterisk and will tell you how to set up your Asterisk system to work with them so any PC in your house can call a real telephone. The "catch" is that these services cost money. And you will need an Internet connection (high-speed). However, you may save money over what your local telephone company charges.

"My high-speed Internet service is digital subscriber line (DSL) over my phone-line. Can I drop the phone-line and keep DSL?

It depends on your carrier. My carrier doesn't offer "naked" DSL (i.e. DSL service and no phone line), but some do. This might seem to negate the use of Asterisk with a VoIP service, but you don't need long distance service from your land-line carrier in this case. And the VoIP service may be cheaper or provide better coverage.

"But can I use a real telephone with Asterisk?"

Sure. But you can't really plug a telephone directly into an Asterisk system or into your local computer network. There are multiple "gotchas" (i.e. each costs money) available to solve this problem:

1. You can get an adapter, called an analog telephone adapter (ATA), that will convert your phone's output into VoIP to go over your computer network to Asterisk.
2. Or you can get a VoIP telephone. Some are available for as low as $60.
3. You can add an adapter card to the PC that supports one or more analog telephones or telephone lines with one or more analog telephones on it. The phone or phones plugged into each adapter become one extension on your Asterisk system. Any phone on the line can pick up answer a ring or joing in a conversation just like a party line. You can run a separate line to the PC so that each analog telephone can have its on extension number and private connection. But, of course, you need an adapter for each phone in that case.

"Can I connect Asterisk to my local phone company line (or lines)?

Yes, there are many companies that provide equipment that will alow your Asterisk PBX to attach to the PSTN directly. This is the second of two ways I mentioned earlier to connect your Asterisk system to the PSTN. Of course, this is another "gotcha" in that the cards or adapters to connect to the PSTN cost money. The more lines you connect to, the more money.

"Does Asterisk work with fax?"

It mostly does. This is one of the flakier parts of Asterisk. Its fax performance is dependent on the quality of all your components such as the fax machine, telephone lines, etc.

Asterisk also has some builtin capability to receive faxes, notify you, and convert to Adobe PDF files and send them to you.

"Is Asterisk programmable?"

Yes very, but another "gotcha". The programs are called Asterisk dialing plans. It doesn't cost money if you program it yourself, but it will take some time to learn. There are numerous Asterisk dialing plans available for free on the Internet. Good-by telemarketers!

"Is it hard to install?"

You can download an almost-ready-to-run system over the Internet. With a little configuration you will be up and running (but see the answer to the next question as to whether you should).

"Any more gotchas?"

As you can probably tell from the length of what precedes (or maybe just by counting the acronyms), Asterisk has a learning curve. Geeky, nerdy types are probably best-suited to setting up, programming, configuring and maintaining Asterisk.

But there are commercial companies that will do it for you. Of course, they charge for their services.

For a modest investment in money and some time for your learning curve you can have a PBX that rivals many large companies. Enjoy!