How to establish remote video / audio connectivity in webrtc iOS

Question

I am using sample code form - https://github.com/stasel/WebRTC-iOS

Trying to establish video/audio call . I have done all initial setup.

1. setup signaling server in two devices and connected. Exchanging SDP.
2. setup peer connection, add media stream added local tracks video and audio
3. send offer form device A, set local description in device A and set remote description in device B.
4. send answer form device B, set local description in device B and set remote description in device A.

Do we need to setup any others details in peer connection for same local network devices (Same IP Address).

Is there any need to exchange ICE candidates details ?

I have implemented same as https://github.com/stasel/WebRTC-iOS

If anyone have idea on webrtc for ios please suggest.