I have deployed the apprtc (https://github.com/webrtc/apprtc), webrtc sample project from Google on my own GAE account. I found that developers have to their own TURN server to support NAT traversal and cannot use Google's TURN server.
Are there any other services that developers have to provide on their own in addition to TURN?
Are there free TURN servers to use?
In addition to TURN, one has to service the signaling server: https://github.com/webrtc/apprtc/tree/master/src/collider