Added re-register mechanism in example app after call ends or fails for more quality of service

Author: Mikael Wills

README.md

@@ -6,9 +6,9 @@ A dart-lang version of the SIP UA stack, ported from [JsSIP](https://github.com/
 
 ## Overview
 - Use pure [dart-lang](https://dart.dev)
-- SIP over WebSocket (use real SIP in your flutter mobile, [desktop](https://flutter.dev/desktop), [web](https://flutter.dev/web) apps)
+- SIP over WebSocket && TCP (use real SIP in your flutter mobile, [desktop](https://flutter.dev/desktop), [web](https://flutter.dev/web) apps)
 - Audio/video calls ([flutter-webrtc](https://github.com/cloudwebrtc/flutter-webrtc)) and instant messaging
-- Support with standard SIP servers such as OpenSIPS, Kamailio, Asterisk and FreeSWITCH.
+- Support with standard SIP servers such as OpenSIPS, Kamailio, Asterisk, 3CX and FreeSWITCH.
 - Support RFC2833 or INFO to send DTMF.
 
 ## Currently supported platforms
@@ -50,9 +50,47 @@ Register with SIP server:
 - [Asterisk](https://github.com/flutter-webrtc/dockers/tree/main/asterisk)
 - FreeSWITCH
 - OpenSIPS
+- 3CX
 - Kamailio
 - or add your server example.
 
+## FAQ's OR ISSUES
+<details>
+
+<summary>expand</summary>
+
+## Server not configured for DTLS/SRTP
+
+WEBRTC_SET_REMOTE_DESCRIPTION_ERROR: Failed to set remote offer sdp: Called with SDP without DTLS fingerprint.
+
+Your server is not sending a DTLS fingerprint inside the SDP when inviting the sip_ua client to start a call.
+
+WebRTC uses encryption by Default, all WebRTC communications (audio, video, and data) are encrypted using DTLS and SRTP, ensuring secure communication. Your PBX must be configured to use DTLS/SRTP when calling sip_ua.
+
+
+## Why isn't there a UDP connection option?
+
+This package uses a WS or TCP connection for the signalling processs to initiate or terminate a session (sip messages).
+Once the session is connected WebRTC transmits the actual media (audio/video) over UDP.
+
+If anyone actually still wants to use UDP for the signalling process, feel free to submit a PR with the large amount of work needed to set it up, packet order checking, error checking, reliability timeouts, flow control, security etc etc.
+
+## SIP/2.0 488 Not acceptable here
+
+The codecs on your PBX server don't match the codecs used by WebRTC
+
+- **opus** (payload type 111, 48kHz, 2 channels)
+- **red** (payload type 63, 48kHz, 2 channels)
+- **G722** (payload type 9, 8kHz, 1 channel)
+- **ILBC** (payload type 102, 8kHz, 1 channel)
+- **PCMU** (payload type 0, 8kHz, 1 channel)
+- **PCMA** (payload type 8, 8kHz, 1 channel)
+- **CN** (payload type 13, 8kHz, 1 channel)
+- **telephone-event** (payload type 110, 48kHz, 1 channel for wideband, 8000Hz, 1 channel for narrowband)
+
+</details>
+
+
 ## NOTE
 Thanks to the original authors of [JsSIP](https://github.com/versatica/JsSIP) for providing the JS version, which makes it possible to port the [dart-lang](https://dart.dev).
 - [José Luis Millán](https://github.com/jmillan)
@@ -69,6 +107,7 @@ The project is inseparable from the contributors of the community.
 - [Robert Sutton](https://github.com/rlsutton1) - Contributor
 - [Gavin Henry](https://github.com/ghenry) - Contributor
 - [Perondas](https://github.com/Perondas) - Contributor
+- [Mikael Wills](https://github.com/mikaelwills) - Contributor
 
 ## License
 dart-sip-ua is released under the [MIT license](https://github.com/cloudwebrtc/dart-sip-ua/blob/master/LICENSE).

example/android/gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-all.zip

example/android/settings.gradle

@@ -18,8 +18,8 @@ pluginManagement {
 
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "7.3.0" apply false
-    id "org.jetbrains.kotlin.android" version "1.7.10" apply false
+    id "com.android.application" version "8.1.0" apply false
+    id "org.jetbrains.kotlin.android" version "1.8.22" apply false
 }
 
 include ":app"

example/lib/main.dart

@@ -1,4 +1,5 @@
 import 'package:dart_sip_ua_example/src/theme_provider.dart';
+import 'package:dart_sip_ua_example/src/user_state/sip_user_cubit.dart';
 import 'package:flutter/foundation.dart'
     show debugDefaultTargetPlatformOverride;
 import 'package:flutter/material.dart';
@@ -60,11 +61,18 @@ class MyApp extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Flutter Demo',
-      theme: Provider.of<ThemeProvider>(context).currentTheme,
-      initialRoute: '/',
-      onGenerateRoute: _onGenerateRoute,
+    return MultiProvider(
+      providers: [
+        Provider<SIPUAHelper>.value(value: _helper),
+        Provider<SipUserCubit>(
+            create: (context) => SipUserCubit(sipHelper: _helper)),
+      ],
+      child: MaterialApp(
+        title: 'Flutter Demo',
+        theme: Provider.of<ThemeProvider>(context).currentTheme,
+        initialRoute: '/',
+        onGenerateRoute: _onGenerateRoute,
+      ),
     );
   }
 }

example/lib/src/dialpad.dart

@@ -1,7 +1,9 @@
 import 'package:dart_sip_ua_example/src/theme_provider.dart';
+import 'package:dart_sip_ua_example/src/user_state/sip_user_cubit.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:logger/logger.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -24,6 +26,9 @@ class _MyDialPadWidget extends State<DialPadWidget>
   SIPUAHelper? get helper => widget._helper;
   TextEditingController? _textController;
   late SharedPreferences _preferences;
+  late SipUserCubit currentUserCubit;
+
+  final Logger _logger = Logger();
 
   String? receivedMsg;
 
@@ -241,6 +246,8 @@ class _MyDialPadWidget extends State<DialPadWidget>
     Color? textColor = Theme.of(context).textTheme.bodyMedium?.color;
     Color? iconColor = Theme.of(context).iconTheme.color;
     bool isDarkTheme = Theme.of(context).brightness == Brightness.dark;
+    currentUserCubit = context.watch<SipUserCubit>();
+
     return Scaffold(
       appBar: AppBar(
         title: Text("Dart SIP UA Demo"),
@@ -345,19 +352,37 @@ class _MyDialPadWidget extends State<DialPadWidget>
 
   @override
   void registrationStateChanged(RegistrationState state) {
-    setState(() {});
+    setState(() {
+      _logger.i("Registration state: ${state.state?.name}");
+    });
   }
 
   @override
   void transportStateChanged(TransportState state) {}
 
   @override
   void callStateChanged(Call call, CallState callState) {
-    if (callState.state == CallStateEnum.CALL_INITIATION) {
-      Navigator.pushNamed(context, '/callscreen', arguments: call);
+    switch (callState.state) {
+      case CallStateEnum.CALL_INITIATION:
+        Navigator.pushNamed(context, '/callscreen', arguments: call);
+        break;
+      case CallStateEnum.FAILED:
+        reRegisterWithCurrentUser();
+        break;
+      case CallStateEnum.ENDED:
+        reRegisterWithCurrentUser();
+        break;
+      default:
     }
   }
 
+  void reRegisterWithCurrentUser() async {
+    if (currentUserCubit.state == null) return;
+    if (helper!.registered) await helper!.unregister();
+    _logger.i("Re-registering");
+    currentUserCubit.register(currentUserCubit.state!);
+  }
+
   @override
   void onNewMessage(SIPMessageRequest msg) {
     //Save the incoming message to DB

example/lib/src/register.dart

@@ -1,4 +1,7 @@
+import 'package:dart_sip_ua_example/src/user_state/sip_user.dart';
+import 'package:dart_sip_ua_example/src/user_state/sip_user_cubit.dart';
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sip_ua/sip_ua.dart';
 import 'package:flutter/foundation.dart' show kIsWeb;
@@ -32,6 +35,8 @@ class _MyRegisterWidget extends State<RegisterWidget>
 
   SIPUAHelper? get helper => widget._helper;
 
+  late SipUserCubit currentUser;
+
   @override
   void initState() {
     super.initState();
@@ -98,54 +103,46 @@ class _MyRegisterWidget extends State<RegisterWidget>
       barrierDismissible: false,
       builder: (BuildContext context) {
         return AlertDialog(
-          title: Text('$alertFieldName is empty'),
-          content: Text('Please enter $alertFieldName!'),
-          actions: <Widget>[
-            TextButton(
-              child: Text('Ok'),
-              onPressed: () {
-                Navigator.of(context).pop();
-              },
-            ),
-          ],
-        );
+            title: Text('$alertFieldName is empty'),
+            content: Text('Please enter $alertFieldName!'),
+            actions: <Widget>[
+              TextButton(
+                child: Text('Ok'),
+                onPressed: () {
+                  Navigator.of(context).pop();
+                },
+              ),
+            ]);
       },
     );
   }
 
-  void _handleSave(BuildContext context) {
+  void _register(BuildContext context) {
     if (_wsUriController.text == '') {
       _alert(context, "WebSocket URL");
     } else if (_sipUriController.text == '') {
       _alert(context, "SIP URI");
     }
 
-    UaSettings settings = UaSettings();
-
-    settings.port = _portController.text;
-    settings.webSocketSettings.extraHeaders = _wsExtraHeaders;
-    settings.webSocketSettings.allowBadCertificate = true;
-    //settings.webSocketSettings.userAgent = 'Dart/2.8 (dart:io) for OpenSIPS.';
-    settings.tcpSocketSettings.allowBadCertificate = true;
-    settings.transportType = _selectedTransport;
-    settings.uri = _sipUriController.text;
-    settings.webSocketUrl = _wsUriController.text;
-    settings.host = _sipUriController.text.split('@')[1];
-    settings.authorizationUser = _authorizationUserController.text;
-    settings.password = _passwordController.text;
-    settings.displayName = _displayNameController.text;
-    settings.userAgent = 'Dart SIP Client v1.0.0';
-    settings.dtmfMode = DtmfMode.RFC2833;
-    settings.contact_uri = 'sip:${_sipUriController.text}';
+    _saveSettings();
 
-    helper!.start(settings);
+       currentUser.register(SipUser(
+        selectedTransport: _selectedTransport,
+        wsExtraHeaders: _wsExtraHeaders,
+        sipUri: _sipUriController.text,
+        port: _portController.text,
+        displayName: _displayNameController.text,
+        password: _passwordController.text,
+        authUser: _authorizationUserController.text));
   }
 
   @override
   Widget build(BuildContext context) {
     Color? textColor = Theme.of(context).textTheme.bodyMedium?.color;
     Color? textFieldFill =
         Theme.of(context).buttonTheme.colorScheme?.surfaceContainerLowest;
+    currentUser = context.watch<SipUserCubit>();
+
     OutlineInputBorder border = OutlineInputBorder(
       borderSide: BorderSide.none,
       borderRadius: BorderRadius.circular(5),
@@ -168,7 +165,7 @@ class _MyRegisterWidget extends State<RegisterWidget>
                     height: 40,
                     child: ElevatedButton(
                       child: Text('Register'),
-                      onPressed: () => _handleSave(context),
+                      onPressed: () => _register(context),
                     ),
                   ),
                 ),

example/lib/src/user_state/sip_user.dart

@@ -0,0 +1,51 @@
+import 'package:sip_ua/sip_ua.dart';
+
+class SipUser {
+  final String port;
+  final String displayName;
+  final String? wsUrl;
+  final String? sipUri;
+  final String password;
+  final String authUser;
+  final TransportType selectedTransport;
+  final Map<String, String>? wsExtraHeaders;
+
+  SipUser({
+    required this.port,
+    required this.displayName,
+    required this.password,
+    required this.authUser,
+    required this.selectedTransport,
+    this.wsExtraHeaders,
+    this.wsUrl,
+    this.sipUri,
+  });
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is SipUser &&
+        other.port == port &&
+        other.displayName == displayName &&
+        other.wsUrl == wsUrl &&
+        other.sipUri == sipUri &&
+        other.selectedTransport == selectedTransport &&
+        other.wsExtraHeaders == wsExtraHeaders &&
+        other.password == password &&
+        other.authUser == authUser;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hashAll([
+      port,
+      displayName,
+      wsUrl,
+      sipUri,
+      password,
+      wsExtraHeaders,
+      selectedTransport,
+      authUser,
+    ]);
+  }
+}

example/lib/src/user_state/sip_user_cubit.dart

@@ -0,0 +1,31 @@
+import 'package:bloc/bloc.dart';
+import 'package:dart_sip_ua_example/src/user_state/sip_user.dart';
+import 'package:sip_ua/sip_ua.dart';
+
+class SipUserCubit extends Cubit<SipUser?> {
+  final SIPUAHelper sipHelper;
+  SipUserCubit({required this.sipHelper}) : super(null);
+
+
+  void register(SipUser user) {
+    UaSettings settings = UaSettings();
+    settings.port = user.port;
+    settings.webSocketSettings.extraHeaders = user.wsExtraHeaders ?? {};
+    settings.webSocketSettings.allowBadCertificate = true;
+    //settings.webSocketSettings.userAgent = 'Dart/2.8 (dart:io) for OpenSIPS.';
+    settings.tcpSocketSettings.allowBadCertificate = true;
+    settings.transportType = user.selectedTransport;
+    settings.uri = user.sipUri;
+    settings.webSocketUrl = user.wsUrl;
+    settings.host = user.sipUri?.split('@')[1];
+    settings.authorizationUser = user.authUser;
+    settings.password = user.password;
+    settings.displayName = user.displayName;
+    settings.userAgent = 'Dart SIP Client v1.0.0';
+    settings.dtmfMode = DtmfMode.RFC2833;
+    settings.contact_uri = 'sip:${user.sipUri}';
+
+    emit(user);
+    sipHelper.start(settings);
+  }
+}

example/pubspec.yaml

@@ -19,15 +19,16 @@ environment:
   flutter: ">=1.10.0"
 
 dependencies:
+  bloc: ^9.0.0
   flutter:
     sdk: flutter
   sip_ua:
     path: ../
   shared_preferences: ^2.2.0
   permission_handler: ^11.1.0
-  flutter_webrtc: ^0.12.4
+  flutter_webrtc: ^0.12.6
   provider: 6.1.2
-  logger: ^2.4.0
+  logger: ^2.5.0
 
 dev_dependencies:
   flutter_test: