WebRTC cannot establish P2P connection in a network intense environment

[phoenix850508]

I've tested using WebRTC Stream Manager in several occasions of web streaming demo, however, I failed to demo video stream via webRTC seemingly due to P2P connection cannot find the right IP.

While using less stable network (mobile hotspot in a crowded area) to connect with NX server, the webRTC websocket's SDP shows two types of ICE candidates:

1. type srflx
2. typ relay

From my understanding, these SDP messages means the webRTC manager uses either STUN or TURN server to help with the P2P connection. However, it still failed to make connection to show video streams.

Is there any way I could fix this problem? A lot of time I'll be in the situation where less stable network connection is expected, and I want to be able to use webRTC to demo video stream because of the low latency advantage.

[chrisczach]

@phoenix850508

Thanks for reporting this issue. To help diagnose the connection problems, I’ll need some additional information.

Debug Information Collection

1. Enable Logging

WebRTCStreamManager.logger = window.console;

Add this before creating connections to enable detailed diagnostics.

2. Connection Diagnostics

Run after attempting connection:

const connections = Object.values(WebRTCStreamManager.EXISTING_CONNECTIONS);
connections.forEach(conn => {
  if (conn?.peerConnection) {
    console.log('Connection State:', {
      ice: conn.peerConnection.iceConnectionState,
      connection: conn.peerConnection.connectionState,
      relay: conn.connectionType?.usingRelay,
      stream: conn.currentStream() === 0 ? 'primary' : 'secondary',
      metrics: conn.getMetrics()
    });
  }
});

Information Needed

• Timing: When does failure occur? (immediate, 5-10s delay, intermittent)
• Error messages: Especially “No bytes received”, “peerConnection failed”, or connection state errors
• Console logs: Full output with debugging enabled
• Environment: Browser/OS, network type, firewall/VPN presence

Connection Phases & Common Failure Points

To help diagnose the issue, it’s important to identify which phase the failure occurs in:

1. Before WebSocket Negotiation

• Connection fails immediately
• Unable to reach signaling server
• Authentication/access token issues

2. During Negotiation

• WebSocket connects but offer/answer exchange fails
• SDP negotiation errors
• ICE candidate gathering issues

3. After Establishing Peer Connection

• Connection established but no media received
• ICE connection state changes (connected → disconnected)
• Network/firewall blocking media packets

4. After Video Playback Starts

• Video plays then stops/freezes
• Quality degradation or intermittent disconnections
• Codec or performance-related issues

Identifying the failure phase and whether it’s consistent or intermittent will significantly help narrow down the root cause.

Please provide the console output with logging enabled and the specific error messages/timing to help identify where in the connection pipeline the failure occurs.

[phoenix850508]

Hi @chrisczach
Thanks for providing the diagnostic logging instruction, I've added the logging code in my repo, the image below is the console from the log

To provide a bit more context about the the failure, I only encounter this issue while using a dynamic IP network in the network intense environment (crowded places). The phase during websocket negotiation is perfectly fine, I can see both of ICE candidates from the client side and from the server side. However, after the ICE candidate exchange, the video element seems to be stuck with no media stream shown.

I'm wondering whether it's the ICE candidate exahange doesn't work out, so the WebRTC failed to established peer connection.

The information needed part I've listed below:
Timing: intermittent, sometimes it works, but most of the time in the network intense environment it doesn't
Error messages: there were no error messages prior adding the logging code, the logging code shows CloseEvent error in the console
Console logs: refer to the image above
Environment: Chrome/Win 11, 4G LTE dynamic IP, currently only router's firewall presented.