I just built an open source SIP server Kamailio and run on my personal server. And I am trying to find some open source IVR or media server that I can configured to this SIP server, and I found Voxeo which is quite powerful, support VXML and CCXML, that is not open source but it is a cloud platform. I configured a SIP number on Kamailio which can routed to Voxeo application when being called.
Just first learned VXML to code the IVR call flow by hand. Using Node.JS to host the VXML file which resided on my server and configured Voxeo to call it. A lot of possibility when VXML can do with Node.JS like WebSocket request to Agent browser screen when IVR call comes, and agent can provide some answer and then media server will playback it to the customer in calls.
Still finding a real open source IVR or media server that can installed on my server. But I know I could not getting the awesome Nuance without giving any fee.
The next I want to achieve is the ability to establish the calls from Google Chrome via WebRTC Link to my SIP Server, maybe via WebSocket, but the challenge is the compatibility of WebRTC’s RTP session link with SIP media server where the actual voice packets transmitted over the calls. If this part of compatibility becomes mature, then there is another chance for call centers for this lower cost SIP client solution.