Two devices on different places connected with different network is not working IOS ( Swift ) through Webrtc

Question

What steps will reproduce the problem?

1. Its working fine for me when i test for 2 or multiple devices locally (both are connected to same network)
2. Its working for me when i test for 2 or multiple devices (both are connected to different networks)
3. Issue arise when i have one device connected with a network in one place and second device with different network on another place. then i got everything is setting correctly like sdps (offer / answer / icecandidates). But state is "checking" and after few seconds it's state change to "closed".

What is the expected result?

(Two devices on different places connected with different network should work)

What do i see instead?

Black screen and its state is "checking" instead of "connected"

What version of the product are you using? On what operating system?

I am using:

 GoogleWebRTC (1.1.21820)  
 xcode (11.5)  
 Iphone 7 (13.5.1)

I have done my best need help please.

Answer 1

The problem arise because you're using only STUN server....so when devices are connected to different network STUN server couldn't Translate Private IP to Public IP....In this case you will use TURN server...! here is a link I hope this will be helpful to understand your problem.

CheckOut this amazing article: https://andrewjprokop.wordpress.com/2014/07/21/understanding-webrtc-media-connections-ice-stun-and-turn/