The most interesting article (to me) in the Jan 31 edition of InfoWorld was one titled Open Source PBXes: Free Flexibility. I’ve been tracking a few open source PBX and softphone projects for awhile now. After reading the PBX article I thought I’d take another look.
The InfoWorld article looks at Asterisk by Digium and SIPxchange by Pingtel. Asterisk is probably the most well known open source PBX package and can run quite well in its open source form. Pingtel has a much more corporate feel. Its core, sipX, is open source, but it appears that that to do anything useful you need commercial extensions from Pingtel. I can’t fault Pingtel for that either. A company has got to make a buck somehow, and some open source is better than no open source at all, I think. There appears to be a nice community growing up around sipX at SIPfoundry.org.
If I had to choose one open source product over the other, I’d probably have to go with Asterisk, as it handles many protocols (SIP, H.323, MGCP, IAX, SCCP) while SIPxchange/sipX focuses exclusively on SIP. The commercial SIPxchange is probably going to be the easiest to administer with its graphical user interface for confiuration and management. On the other hand, if you have a linux guru on staff you should be able to pull off an Asterisk configuration without too much trouble.
Most (if not all) PBX systems require some sort of hardware to interface with your external lines and internal network. These open source alternatives are no different, although the processing power requirements are very low. InfoWorld tested out these PBX systems on surplus Pentium desktop systems and they performed just fine. You’ll need some sort of hardware to hook in to your phone lines and phone system, but open source PBX software running on modest hardware can quite proably reduce the costs of your PBX.
Update: I really should have dug a little deeper, as I forgot to mention GNU Bayonne, which has probably been around longer than most. Erik also pointed me to Voicetronix, which looks like a good place for hardware as well as open source PBX software.