Flutter下SIP-UA+WebRTC实现VoIP遇RTP超时问题求助

我正在使用Flutter开发适用于Android和iOS的VoIP应用，采用dart sip_ua库。目前已成功注册到信令服务器、接收呼叫，且客户端可连接ICE服务器，但呼叫会在30秒后因RTP超时错误终止。

错误日志 #

I/flutter ( 6747): Record-Route: <sip:192.168.0.7:5080;transport=ws;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
I/flutter ( 6747): Record-Route: <sip:192.168.0.7;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
D/FlutterWebRTCPlugin( 6747): onAddTrack
D/FlutterWebRTCPlugin( 6747): onIceGatheringChangeGATHERING
D/FlutterWebRTCPlugin( 6747): onConnectionChangeCONNECTING
D/FlutterWebRTCPlugin( 6747): onIceCandidate
D/FlutterWebRTCPlugin( 6747): onIceGatheringChangeCOMPLETE
I/flutter ( 6747): Record-Route: <sip:192.168.0.7:5080;transport=ws;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
I/flutter ( 6747): Record-Route: <sip:192.168.0.7;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
I/flutter ( 6747): m=audio 56441 RTP/SAVPF 0 8 101
D/FlutterWebRTCPlugin( 6747): onIceCandidate
I/flutter ( 6747): m=audio 56441 RTP/SAVPF 0 8 101
D/FlutterWebRTCPlugin( 6747): onConnectionChangeFAILED
I/flutter ( 6747): [2024-01-02 00:28:28.596] Level.debug sip_ua_helper.dart:249 ::: call ended with cause: Code: [408], Cause: RTP Timeout, Reason: RTP Timeout
D/FlutterWebRTCPlugin( 6747): onConnectionChangeCLOSED
I/flutter ( 6747): Route: <sip:192.168.0.7:5080;transport=ws;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
I/flutter ( 6747): Route: <sip:192.168.0.7;r2=on;lr=on;nat=yes;rtp=bridge;rtp=ws>
I/flutter ( 6747): Reason: SIP ;case=408; text="RTP Timeout"

SIP UA代码 #

import 'package:flutter/material.dart';
import 'package:flutter_callkit_incoming/entities/entities.dart';
import 'package:uuid/uuid.dart';
import 'package:flutter_callkit_incoming/flutter_callkit_incoming.dart';
import 'package:sip_ua/sip_ua.dart';
import 'package:flutter_webrtc/flutter_webrtc.dart';

void main() {
  runApp(const MyApp());
  var uuid = const Uuid();
  var sipHelper = SIPUAHelper();

  SipEvents sipevent = SipEvents();
  sipevent._initRenderers();

  var ua = UaSettings();
  ua.authorizationUser = '2167';
  ua.password = 'XXXX';
  ua.webSocketUrl = 'wss://turn.konza.go.ke/ws';
  ua.uri = 'sip:2167@XX.XX.XX.XX';
  ua.iceGatheringTimeout = 3000;
  ua.iceServers = <Map<String, String>>[
    <String, String>{
      'url': 'turn:turn.konza.go.ke:3478',
      'username': 'goipvoice',
      'credential': 'XXXXX',
    },
  ];
  ua.register = true;
  sipHelper.start(ua);
  print("listeners here");
  print(sipHelper.listeners);
  sipHelper.addSipUaHelperListener(sipevent);
}

class SipEvents extends SipUaHelperListener {
  final RTCVideoRenderer? _localRenderer = RTCVideoRenderer();
  final RTCVideoRenderer? _remoteRenderer = RTCVideoRenderer();
  double? _localVideoHeight;
  double? _localVideoWidth;
  final mediaConstraints = <String, dynamic>{
    'audio': true,
    'video': false,
  };
  MediaStream? _localStream;
  MediaStream? _remoteStream;
  late MediaStream mediaStream;

  void _handleAccept() async {
    mediaStream = await navigator.mediaDevices.getUserMedia(mediaConstraints);
  }

  void _handelStreams(CallState event) async {
    MediaStream? stream = event.stream;
    if (event.originator == 'local') {
      if (_localRenderer != null) {
        _localRenderer!.srcObject = stream;
      }
      if (!WebRTC.platformIsDesktop) {
        event.stream?.getAudioTracks().first.enableSpeakerphone(false);
      }
      _localStream = stream;
    }
    if (event.originator == 'remote') {
      if (_remoteRenderer != null) {
        _remoteRenderer!.srcObject = stream;
      }
      _remoteStream = stream;
    }
  }

  void _initRenderers() async {
    if (_localRenderer != null) {
      await _localRenderer!.initialize();
    }
    if (_remoteRenderer != null) {
      await _remoteRenderer!.initialize();
    }
  }

  @override
  Future<void> callStateChanged(Call call, CallState state) async {
    String stateName = state.state.name;
    print("new Call $stateName");
    print(state.state.name);
    if (stateName == "PROGRESS") {
      print("call has started");
      try {
        mediaStream =
            await navigator.mediaDevices.getUserMedia(mediaConstraints);
        call.answer(SIPUAHelper().buildCallOptions(true),
            mediaStream: mediaStream);
        print("gotten media");
        var peerConnection = call.peerConnection;
        print("peer connection $peerConnection");
      } catch (e) {}
    }
    if (stateName == "STREAM") {
      _handelStreams(state);
    }
  }

  @override
  void onNewMessage(SIPMessageRequest msg) {
    print("new sip mesasge");
  }

  @override
  void onNewNotify(Notify ntf) {
    print("new notify");
  }

  @override
  void registrationStateChanged(RegistrationState state) {
    print("new registration");
  }

  @override
  void transportStateChanged(TransportState state) {
    print("new transport");
  }
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(
          title: 'Flutter Demo Home Page hot reload count here'),
    );
  }
}

class MyHomePage extends StatefulWidget implements SipUaHelperListener {
  const MyHomePage({super.key, required this.title});

  final String title;

  void initState() {
    SIPUAHelper().addSipUaHelperListener(this);
  }

  @override
  State<MyHomePage> createState() => _MyHomePageState();

  @override
  void callStateChanged(Call call, CallState state) {
    print("new message");
  }

  @override
  void onNewMessage(SIPMessageRequest msg) {
    print("new message");
  }

  @override
  void onNewNotify(Notify ntf) {
    print("new message");
  }

  @override
  void registrationStateChanged(RegistrationState state) {
    print("new message");
  }

  @override
  void transportStateChanged(TransportState state) {
    print("new message");
  }
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    var uuid = const Uuid();
    var callid = uuid.v4();

    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times here:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            ElevatedButton(
              onPressed: () async {
                print("action button pressed");
                CallKitParams params = CallKitParams(
                    id: callid,
                    nameCaller: 'Emmanuel',
                    appName: 'go mobile',
                    type: 0,
                    duration: 30000,
                    textAccept: 'Answer',
                    textDecline: 'Decline',
                    handle: '0716597086',
                    extra: {'userId': '1a2b3c4d'},
                    missedCallNotification: const NotificationParams(
                      id: 234,
                      showNotification: true,
                      callbackText: "Call back",
                    ),
                    android: const AndroidParams(
                      ringtonePath: 'system_ringtone_default',
                      isCustomNotification: true,
                      isShowLogo: false,
                    ));
                await FlutterCallkitIncoming.showCallkitIncoming(params);
                FlutterCallkitIncoming.onEvent.listen((event) {
                  print(event?.event);
                  switch (event?.event) {
                    case Event.actionCallAccept:
                      FlutterCallkitIncoming.setCallConnected(callid);
                      print("call accepter");
                      break;
                    default:
                  }
                });
              },
              child: const Text('Incoming Call'),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

我刚接触Flutter，但具备WebRTC JavaScript开发经验。已尝试更换ICE服务器并验证其与信令服务器的可用性，仍未解决问题，恳请协助。

内容的提问来源于stack exchange，提问作者emmanuel simiyu