Optimizing Self-Hosted WebRTC Video Streaming: Overcoming WSS Compatibility Challenges in Firefox

In today’s interconnected world, real-time media streaming has become essential for many applications—from remote monitoring to collaborative tools. Setting up a self-hosted WebRTC stream from a mobile device to a laptop can be straightforward, but browser inconsistencies can pose unexpected hurdles.

Scenario Overview

Imagine a setup where a user wants to stream their phone’s camera feed directly to their laptop over a LAN. The signaling mechanism relies on WebSockets secured with WebSocket Secure (WSS) over HTTPS, using a self-signed SSL certificate. The signaling server is implemented with Python and WebSockets, while the media is delivered via a simple HTTPS server with a self-signed certificate.

This configuration works flawlessly in Chrome on both devices, but in Firefox, the WebSocket connection fails to establish, presenting an error along the lines of:

“Firefox can’t establish a connection to the server at wss://:8765.”

Troubleshooting Steps and Insights

Given that Chrome handles the connection seamlessly, the core issue appears to be specific to Firefox’s handling of self-signed certificates and WSS connections. Here are some steps and considerations to help resolve the problem:

1. Explicitly Trust the Self-Signed Certificate in Firefox

2. When accessing the HTTPS page, Firefox prompts you to add an exception for the self-signed cert.

3. Ensure that you accept and permanently trust this certificate.

4. After accepting, restart Firefox and test the WebSocket connection again.

5. Verify Certificate Validity and Matching Keys

6. Confirm that both the certificate (cert.pem) and the private key (key.pem) are correctly generated, valid, and correspond to each other.

7. Use tools like OpenSSL to inspect the certificate details and ensure they match.

8. Ensure Proper WebSocket URL and Protocol

9. Double-check that the WebSocket connection URL strictly uses the wss:// protocol.

10. Confirm that the URL matches the server’s listening address and port.

11. Check Browser Console and Network Logs

12. Use Firefox Developer Tools to review console errors and network activity.

13. Ensure no SSL errors or certificate warnings are suppressed or ignored.

14. Review the WebSocket Server Configuration

15. Ensure that the server is correctly configured to accept WSS connections and that it’s listening on the correct port.

16. Verify that the server’s SSL