.env

@@ -8,3 +8,4 @@ SERVER_KEY="./server/ssl/key.pem"
 ENABLE_UDP=true
 ENABLE_TCP=true
 PREFER_UDP=true
+PREFER_TCP=false

app.js

@@ -15,7 +15,8 @@ const mediasoup = require('mediasoup');
 const isUdpEnabled = process.env.ENABLE_UDP === 'true';
 const isTcpEnabled = process.env.ENABLE_TCP === 'true';
 const isUdpPreferred = process.env.PREFER_UDP === 'true';
-let initialConnection = isUdpPreferred ? 'udp' : 'tcp';
+const isTcpPreferred = process.env.PREFER_TCP === 'true';
+let currentConnectionType = isUdpPreferred ? 'udp' : 'tcp';
 
 let worker;
 /**
@@ -562,21 +563,29 @@ const createWebRtcTransportLayer = async (callId, callback) => {
       enableUdp: isUdpEnabled,
       enableTcp: isTcpEnabled,
       preferUdp: isUdpPreferred,
+      preferTcp: isTcpPreferred,
+      iceConsentTimeout: 3
     };
 
     // https://mediasoup.org/documentation/v3/mediasoup/api/#router-createWebRtcTransport
     let transport = await videoCalls[callId].router.createWebRtcTransport(webRtcTransport_options);
 
+    // `iceselectedtuplechange`: Fires when ICE switches transport (e.g., UDP → TCP).
     transport.on('iceselectedtuplechange', (selectedTuple) => {
       const { protocol } = selectedTuple;
-      const switchedTo = protocol === 'udp' ? 'tcp' : 'udp';
-
-      if (initialConnection !== protocol) {
-        console.warn(`⚠️ ${protocol.toUpperCase()} blocked! Switching to ${switchedTo.toUpperCase()} for callId: ${callId}`);
-        initialConnection = protocol;
+      if (currentConnectionType !== protocol) {
+        console.warn(`⚠️ ${currentConnectionType.toUpperCase()} blocked! Switching to ${protocol.toUpperCase()} for callId: ${callId}`);
+        currentConnectionType = protocol;
       }
     });
 
+    // `icestatechange`: Fires when ICE connection state changes (e.g., new, connected, failed).
+    transport.on('icestatechange', (iceState) => {
+      console.log(`[ICE STATE CHANGE] callId: ${callId} | State: ${iceState}`);
+      if (iceState === 'failed' || iceState === 'disconnected') {
+        console.warn(`⚠️ ICE failure detected for callId: ${callId}! Possible UDP blockage.`);
+      }
+    });
 
     // Handler for when DTLS(Datagram Transport Layer Security) changes
     transport.on('dtlsstatechange', (dtlsState) => {

package.json

@@ -16,7 +16,7 @@
     "@types/express": "^4.17.13",
     "dotenv": "^16.0.1",
     "express": "^4.18.1",
-    "mediasoup": "^3.10.4",
+    "mediasoup": "^3.15.5",
     "mediasoup-client": "^3.6.54",
     "parcel": "^2.7.0",
     "socket.io": "^2.0.3",