Taking the plunge into an opensource phone system can be a little unnerving, even for the most opensource of us. It's one decision I have never regretted!
About four years ago, we started looking into single points of failure around the company. The phone system is an integral part of our day to day business and it's the one area that lacked redundancy. At the time, we were running a Cisco 7750 CallManager with 115 extensions on Cisco 7910, 7940 and 7960s. The cost to duplicate the system itself to prevent a long term outage was high enough that we were never going to see the funding. So we started looking for alternatives.
. Asterisk is released under the
, so that means free! I don't think it was even at version 1.0 at the time, but we decided to start testing. After a few weeks of playing, we had about 75% of the Cisco system duplicated and it was running on my laptop. The Cisco CallManager was at version 3.x and ran on three separate blades. One had the phone system portion, one held "Unity" which was the voicemail part and the last was the T1 card. We also had external equipment to handle the music on hold. And I mean CD changers, external USB sound cards, etc... And all of this wrapped around a single PRI and a few FXO and FXS ports to support the paging system.
I was really impressed with Asterisk. Once we had a number of phones talking to each other and all of the extensions, voicemail and music on hold working, we ordered a few cards for the new Asterisk server. One was a Digium T1 card and the other had two FXO and two FXS ports. We stuck these in a homebuilt server we had recently retired from other applications and tested some more.
At this point in time, the CallManager was wrecking on a weekly basis and needed rebooted every Sunday. And it took over 15 minutes for everything to come back up and settle out. So we kept on testing and tinkering in hopes we would someday convince management that this was going to be a good idea.
Our time came before we anticipated. The Unity blade wrecked late on a Friday evening. We called Cisco and the support was amazing. They had absolutely no idea what a CallManager 7750 was. After 4 hours or so, they came up a procedure that was going to take almost 3 days to get everything back the way it was after we got the parts. This was our chance!! We approached management with a
WORKING version of the Asterisk phone system. And this was not just a make the phone ring demonstration, we were going to web pages and clicking links and making phones ring. We had it calling cell phones and
SAYING what was going on the server room. Text to speech!!
The possibilities were endless. If we could dream it up, we could make the phone system do it. Management agreed that the cost was certainly justified and they let us proceed. In a few short months, that opensource phone system will be in production for three years!!
Here's a few reasons why Asterisk might make sense for your situation.
1) Asterisk is GPL opensource software. No software costs or recurring licensing.
2) Runs on linux so the OS is extremely stable, no cost and comes in a number of flavors.
3) Everything needed to backup and maintain the system is freely available in Linux. No need for 3rd party apps.
4) Extending the functionality using AGI is easy and can be done in a myriad of programming languages.
5) Repetitive tasks can be scripted making administration extremely simple.
6) Many options for pre-packaged Asterisk solutions in the event you want to use a GUI.
7) More than likely, you can reuse your existing phones if they are VOIP capable.
8) Runs on many types of hardware. You are no longer restricted to what the manufacturer provides or forces you to use.
If you want more details on how we did it, let me know!
Craig Deering
Network Engineer
Astro Shapes, Inc. -
Aluminum ExtrusionsWebsite -
http://www.astroshapes.com
