We recently started using WebRTC to transmit video from Raspberry Pi's where I work. There were a lot of gotchas that weren't obvious to someone who's never worked with VOIP or related technology: STUN and TURN servers[0], 300 seconds idle timeouts that shouldn't affect the connection but killed the video stream regardless, and dropped calls which forced us to reboot the Pi.
In the end we managed to get something smooth working with UV4L[1] on a RPi costing us a fraction of the previous solution.
[0] http://numb.viagenie.ca/ has a free one