Endpoint already negotiated (Code:40208, Type:null, Data: {"type":"SDP_END_POINT_ALREADY_NEGOTIATED"})

[alylhb]

I am testing the project kurento\tutorials\java\group-call. When the first user enters, there is no problem, but when the second user joins the meeting, the server throws an error. I haven't found any relevant solutions yet.

The error occurs in the getEndpointForUser method within the UserSession.java file:

public void receiveVideoFrom(UserSession sender, String sdpOffer) throws IOException {
    log.info("USER {}: connecting with {} in room {}", this.name, sender.getName(), this.roomName);

    log.trace("USER {}: SdpOffer for {} is {}", this.name, sender.getName(), sdpOffer);

    >final String ipSdpAnswer = this.getEndpointForUser(sender).processOffer(sdpOffer);
    final JsonObject scParams = new JsonObject();
    scParams.addProperty("id", "receiveVideoAnswer");
    scParams.addProperty("name", sender.getName());
    scParams.addProperty("sdpAnswer", ipSdpAnswer);

    log.trace("USER {}: SdpAnswer for {} is {}", this.name, sender.getName(), ipSdpAnswer);
    this.sendMessage(scParams);
    log.debug("gather candidates");
    this.getEndpointForUser(sender).gatherCandidates();
  }

2024-03-27 16:02:59.992 ERROR 3632 --- [nio-8443-exec-7] w.s.h.ExceptionWebSocketHandlerDecorator : Closing session due to exception for StandardWebSocketSession[id=43519bbd-e49c-9cbc-cc42-abe452db9818, uri=wss://localhost:8443/groupcall]

org.kurento.client.internal.server.KurentoServerException: Endpoint already negotiated (Code:40208, Type:null, Data: {"type":"SDP_END_POINT_ALREADY_NEGOTIATED"})
	at org.kurento.client.internal.transport.jsonrpc.RomClientJsonRpcClient.sendRequest(RomClientJsonRpcClient.java:264) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.transport.jsonrpc.RomClientJsonRpcClient.invoke(RomClientJsonRpcClient.java:117) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.transport.jsonrpc.RomClientJsonRpcClient.invoke(RomClientJsonRpcClient.java:99) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.client.RomManager.invoke(RomManager.java:162) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.client.RemoteObject.invoke(RemoteObject.java:186) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.client.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:187) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.client.RemoteObjectInvocationHandler.internalInvoke(RemoteObjectInvocationHandler.java:139) ~[kurento-client-7.0.0.jar:7.0.0]
	at org.kurento.client.internal.client.DefaultInvocationHandler.invoke(DefaultInvocationHandler.java:39) ~[kurento-client-7.0.0.jar:7.0.0]
	at com.sun.proxy.$Proxy123.processOffer(Unknown Source) ~[na:na]
	at org.kurento.tutorial.groupcall.UserSession.receiveVideoFrom(UserSession.java:117) ~[classes/:na]
	at org.kurento.tutorial.groupcall.CallHandler.handleTextMessage(CallHandler.java:73) ~[classes/:na]
	at org.springframework.web.socket.handler.AbstractWebSocketHandler.handleMessage(AbstractWebSocketHandler.java:43) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.handler.WebSocketHandlerDecorator.handleMessage(WebSocketHandlerDecorator.java:75) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.handler.LoggingWebSocketHandlerDecorator.handleMessage(LoggingWebSocketHandlerDecorator.java:56) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.handler.ExceptionWebSocketHandlerDecorator.handleMessage(ExceptionWebSocketHandlerDecorator.java:58) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.handleTextMessage(StandardWebSocketHandlerAdapter.java:114) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.access$000(StandardWebSocketHandlerAdapter.java:43) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:85) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:82) ~[spring-websocket-5.3.27.jar:5.3.27]
	at org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:390) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.server.WsFrameServer.sendMessageText(WsFrameServer.java:129) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:484) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:284) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:130) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:84) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.server.WsFrameServer.doOnDataAvailable(WsFrameServer.java:183) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.server.WsFrameServer.notifyDataAvailable(WsFrameServer.java:163) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.upgradeDispatch(WsHttpUpgradeHandler.java:152) ~[tomcat-embed-websocket-9.0.74.jar:9.0.74]
	at org.apache.coyote.http11.upgrade.UpgradeProcessorInternal.dispatch(UpgradeProcessorInternal.java:60) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:57) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:926) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1791) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.74.jar:9.0.74]
	at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]