I've been a happy Vbuzzer customer too, as it happens, and have even used the VOIP system to record phone calls for broadcast. I haven't heard much about Net2Phone in a while, though. They were one of the very first VOIP solutions, as I recall.

But on to your question! Asterisk is another way-cool open source application, as you note. "Asterisk is a complete PBX in software. It runs on Linux, BSD, Windows and OS X and provides all of the features you would expect from a PBX and more. Asterisk does voice over IP in four protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware."

But there's more: "Asterisk provides Voicemail services with Directory, Call Conferencing, Interactive Voice Response, Call Queuing. It has support for three-way calling, caller ID services, ADSI, IAX, SIP, H.323 (as both client and gateway), MGCP (call manager only) and SCCP/Skinny. Check the Features section for a more complete list."

I don't even know what all those acronyms are, but it's impressive!

Digging around, I found that the VOIP info.org site has a wealth of information on Asterisk and quite a bit more about Voice over IP telephony solutions. For your specific interoperability question, you'll find both of these links invaluable:

  •   Asterisk settings for Net2Phone VOIP
  •   Asterisk settings for Vbuzzer VOIP

Those should get you up and online. And when you do get Asterisk running, do pop back and let us know how it works. It sure sounds wonderful for a small business!