Intro Finally, I could try WebRTC. I used the code what I had wrote last time. [Nest.js] Use WebSocket with ws First, I accessed Camera and Mic from Web browser. After that, I opened two client pages and connected them by WebSocket and WebRTC. I referred MDN sample. samples-server/s/webrtc-from-chat at master · mdn/samples-server · GitHub And I also referred this. Building a WebRTC video broadcast using Javascript Access Camera and Mic Adapter.js According to MDN documents, I should install Adapter.js for interoperability between Web browsers. WebRTC API - Web APIs | MDN GitHub - webrtc/adapter: READ ONLY FORK: Shim to insulate apps from spec changes and prefix differences. Latest adapter.js release: But at least in this time, I felt I didn't have to do that. Thus, I didn't install it. getUserMedia I could access Camera and Mic by "getUserMedia". [client-side] index.html <!DOCTYPE html> <html> <head> <title>Index page...