I have android WebRTC Android demo app code running with https://apprtc.appspot.com/ server.
But what i want to archive is, I want to replace the server https://apprtc.appspot.com/ with my own server, i want to also modify/remove the part of the code where it communicants with the server as my server communicates differently. 
I want to keep the WebRTC related API calls as it is, and only replace the part of the source code which is communicating with the https://apprtc.appspot.com/ server.   
So basically i want to know, what are the WebRTC APIs that i must call for allowing AV calls using my server, I have STUN/TURN and registration servers.
I just want to reuse the core WebRTC functionality only and write app on top of it.
Can someone please guide me on this!
Thanks in advance.