While configuring my backup server, it occurred to me that this would be an ideal time to try working with Asterisk, the free VOIP solution available for Linux. Naturally, this entails re-doing much of what I have already done with Samba, as I chose FreeBSD as my operating system. I'll have to strip it and go with CentOS instead. Sigh.
The Asterisk site claims that Asterisk is a complete PBX in software. It runs on Linux, BSD and MacOSX and provides all of the features you would expect from a PBX and more. Asterisk does voice over IP in many protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware. However, my research has indicated that it runs best on Linux, so Linux it is.
I'll keep you posted. And this time I'll take notes.