I finally have it all working perfectly. Last year I became interested in the Asterisk@Home project. After downloading a copy of the .iso I went out and bought an old POS Dell OptiPlex GX1 that would become a dedicated CentOS/Asterisk@Home server.

Over the course of the past year I've gradually upgraded the system, learned about VOIP, Asterisk, and the whole brave new world of internet telephony. Fricking cool shit. Within this past year Asterisk@Home eventually became Trixbox, and the reliability and the maturity of this technology has increased steadily.

After cutting my teeth learning to create a basic Trixbox home server I signed up for a VOIP service account with AXVoice--who offer a flat rate and compatibility with Asterisk. Part of the service includes a telephone number in any area code you want. This is important because of the "virtual" nature of IP telephony: your server can be in one place and serve a phone number in any location across the country. This is really cool: one application of this is it allows you to make "local" calls to home, friends, family, and work while you're on the road any where in the country.

After using my VOIP server and service with a "softphone" (a virtual telephone application you run on your desktop or laptop computer) for a few months I decided it was time to upgrade the system with a neat little hardware device called an Analog Telephone Adapter (or ATA). These devices act as a network bridge between analog phones and digital VOIP systems: essentially you plug in an ethernet cable and a regular home phone and dial away. I decided to purchase an Sipura SPA-2102, which is a little router that includes two RJ-11 jacks.

Configuring this little beast can be tricky, and luckily there is ample information on the web to help noobs like me. The SPA-2102 has an integrated web server so you can do all your configuration with a web-browser--which is much more convenient than using the mini voice server that's built in. Basically you assign it an IP address and supply it with the necessary extension and account credentials so that it will connect with your Asterisk server. Of course, you need to create a new extension in Asterisk so that the SPA-2102 can connect to it as well!

I finally got everything figured out and connected a RadioShack wireless phone to the SPA-2102. Believe it or not it rings and acts just like a normal phone--which is no small miracle. But in addition to a "normal" phone that makes calls using the internet Asterisk also gives you all the bells and whistles you normally only get in the office: voicemail, email notification of voicemail, call forwarding, conference calling, etc etc. Cool.

As I mentioned earlier, Asterisk and IP telephony give you all kinds of other features besides voicemail and the other features I listed previously. I also have a few custom scripts set up so that I can actually dial in to my Asterisk box from another number and have it call me back in such a way that I can then place calls from it. In plain english, this means that I can call my VOIP telephone number from my cell phone on the road, punch in a few codes, and have the Asterisk server call me back and provide a dial tone...which allows me to make a call "from" my VOIP phone number. This is a sweet feature for business travelers tired of paying exorbitant long distance fees from hotel telephones.

Another sweet feature is the ability to create a "digital receptionist" and interactive voice menus that can route calls to specific people and extensions. It's also a great way to screen out annoying automated calls, marketers, surveys, etc.

Here's a diagram of what my home network looks like: