I’ve stumbled upon the word FreeSWITCH during a research I was conducting the last few days and as it turns out, FreeSWITCH is a soft-switch application designed with modularity in mind. It can act as a full-blown PBX or regular soft-switch for routing actions. It integrates with Jabber (googletalk), SIP, H323, IAX naturally. Seems like it is still in early development but looks like a promising new voip application never-the-less.
Liran Tal is the author of the book Node.js Secure Coding: Defending Against Command Injection Vulnerabilities