Merge branch 'develop'

Fix client dead lock and protocol version issues.
Renamed MqttServerAdapter to MqttTcpServerAdapter
2026-10-15 00:15:15 +08:00 · 2018-04-11 21:22:54 +02:00 · 2018-04-11 21:22:08 +02:00 · 2018-04-06 22:49:41 +02:00 · 2018-04-05 23:40:05 +02:00 · 2018-04-05 23:39:10 +02:00
252 changed files with 8163 additions and 4856 deletions
@@ -197,7 +197,7 @@ ClientBin/
 *.dbmdl
 *.dbproj.schemaview
 *.jfm
-*.pfx
+# *.pfx
 *.publishsettings
 orleans.codegen.cs

@@ -289,3 +289,7 @@ __pycache__/


 Build/nuget.exe
+*.js
+*.map
+
+/Tests/MQTTnet.TestApp.NetCore/RetainedMessages.json
@@ -0,0 +1,28 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>MQTTnet.AspNetCore</id>
+    <version>2.7.4</version>
+    <authors>Christian Kratky</authors>
+    <owners>Christian Kratky</owners>
+    <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
+    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
+    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
+    <releaseNotes>* Updated to MQTTnet 2.7.4.
+    </releaseNotes>
+    <copyright>Copyright Christian Kratky 2016-2018</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <dependencies>
+      <group targetFramework="netstandard2.0">
+        <dependency id="MQTTnet" version="2.7.4" />
+      </group>
+    </dependencies>
+  </metadata>
+
+  <files>
+    <!-- .NET Standard 2.0 -->
+    <file src="..\Frameworks\MQTTnet.AspNetCore\bin\Release\netstandard2.0\MQTTnet.AspNetCore.*" target="lib\netstandard2.0\"/>
+  </files>
+</package>
@@ -0,0 +1,47 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>MQTTnet.Extensions.Rpc</id>
+    <version>2.6.0</version>
+    <authors>Christian Kratky</authors>
+    <owners>Christian Kratky</owners>
+    <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
+    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
+    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <description>This is a extension library which allows executing synchronous device calls including a response using MQTTnet.</description>
+    <releaseNotes>* Initial version.
+    </releaseNotes>
+    <copyright>Copyright Christian Kratky 2016-2017</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <dependencies>
+      <group targetFramework="netstandard2.0">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />
+      </group>
+      <group targetFramework="netstandard1.3">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />  
+      </group>
+
+      <group targetFramework="netstandard2.0">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />
+      </group>
+      
+      <group targetFramework="uap10.0">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />
+      </group>
+        
+      <group targetFramework="net452">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />
+      </group>
+
+      <group targetFramework="net461">
+        <dependency id="MQTTnet" version="2.6.0-rc1" />
+      </group>
+    </dependencies>
+  </metadata>
+
+  <files>
+    <!-- .NET Standard 2.0 -->
+    <file src="..\Frameworks\MQTTnet.AspNetCore\bin\Release\netstandard2.0\MQTTnet.AspNetCore.*" target="lib\netstandard2.0\"/>
+  </files>
+</package>
@@ -2,54 +2,67 @@
 <package >
  <metadata>
    <id>MQTTnet</id>
-    <version>2.4.0</version>
+    <version>2.7.4</version>
    <authors>Christian Kratky</authors>
    <owners>Christian Kratky</owners>
    <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
    <requireLicenseAcceptance>false</requireLicenseAcceptance>
-    <description>MQTTnet is a .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
-    <releaseNotes>* [Server] Added an event which is fired when a client has disconnected.
-* [Server] Added support for retained application messages
-* [Server] Added support for saving and loading retained messages
-* [Server] The client connection is now closed if sending of one pending application message has failed
-* [Server] Fixed handling of _Dup_ flag (Thanks to haeberle)
-* [Core] Optimized exception handling
-* [Core] Mono is now also supported (Thanks to JTrotta)
-* [Client] The options are now passed in _ConnectAsync_ (Breaking change! Read Wiki for examples)
-* [Core] Trace class renamed to _MqttNetTrace_ (Breaking change!)
-* [Client] Extended certificate validation options (Breaking change!)
-* [Client] Added static certificate validation callback (NetFramework, NetStandard) / ignorable certificate errors (UniversalWindows) to _MqttTcpChannel_
+    <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
+    <releaseNotes> * [Client] Fixed a deadlock while the client disconnects.
+* [Client] Fixed broken support for protocol version 3.1.0.
+* [Server] The _MqttTcpServerAdapter_ is now added to the ASP.NET services.
+* [Server] _MqttServerAdapter_ is renamed to _MqttTcpServerAdapter_ (BREAKING CHANGE!).
+* [Server] The server no longer sends the will message of a client if the disconnect was clean (via _Disconnect_ packet).
+* [Server] The application message interceptor now allows closing the connection.
+* [Server] Added a new flag for the _ClientDisconnected_ event which contains a value indicating whether the disconnect was clean (via _Disconnect_ packet).
    </releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2017</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M</tags> 
+    <copyright>Copyright Christian Kratky 2016-2018</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
    <dependencies>

      <group targetFramework="netstandard1.3">
-        <dependency id="NETStandard.Library" version="1.6.1" />
+        <dependency id="NETStandard.Library" version="1.3.0" />
        <dependency id="System.Net.Security" version="4.3.2" />
+        <dependency id="System.Net.WebSockets" version="4.3.0" />
+        <dependency id="System.Net.WebSockets.Client" version="4.3.1" />      
+      </group>
+
+      <group targetFramework="netstandard2.0">
+        <dependency id="NETStandard.Library" version="2.0.0" />
+        <dependency id="System.Net.Security" version="4.3.2" />
+        <dependency id="System.Net.WebSockets" version="4.3.0" />
+        <dependency id="System.Net.WebSockets.Client" version="4.3.1" />
      </group>
      
      <group targetFramework="uap10.0">
-        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="5.4.0" />
+        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="5.4.1" />
+      </group>
+        
+      <group targetFramework="net452">
      </group>

+      <group targetFramework="net461">
+      </group>
+      
    </dependencies>
  </metadata>

  <files>
+    
    <!-- .NET Standard 1.3 -->
-    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\netstandard1.3\MQTTnet.Core.*" target="lib\netstandard1.3\"/>
    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
+    
+    <!-- .NET Standard 2.0 -->
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\netstandard2.0\MQTTnet.*" target="lib\netstandard2.0\"/>

    <!-- Universal Windows -->
-    <file src="..\Frameworks\MQTTnet.UniversalWindows\bin\Release\MQTTnet.Core.*" target="lib\uap10.0\"/>
-    <file src="..\Frameworks\MQTTnet.UniversalWindows\bin\Release\MQTTnet.*" target="lib\uap10.0\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\uap10.0\MQTTnet.*" target="lib\uap10.0\"/>

    <!-- .NET Framework -->
-    <file src="..\Frameworks\MQTTnet.NetFramework\bin\Release\MQTTnet.Core.*" target="lib\net45\"/>
-    <file src="..\Frameworks\MQTTnet.NetFramework\bin\Release\MQTTnet.*" target="lib\net45\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net452\MQTTnet.*" target="lib\net452\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net461\MQTTnet.*" target="lib\net461\"/>
    
  </files>
 </package>
@@ -1,12 +1,35 @@
-param([string]$version)
+param([string]$assemblyVersion, [string]$nugetVersion)

-if ([string]::IsNullOrEmpty($version)) {$version = "0.0.1"}
+if ([string]::IsNullOrEmpty($assemblyVersion)) {$assemblyVersion = "0.0.1"}
+if ([string]::IsNullOrEmpty($nugetVersion)) {$nugetVersion = "0.0.1"}

-$msbuild = "MSBuild.exe"
-&$msbuild ..\Frameworks\MQTTnet.NetFramework\MQTTnet.NetFramework.csproj /t:Build /p:Configuration="Release"
-&$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release"
-&$msbuild ..\Frameworks\MQTTnet.UniversalWindows\MQTTnet.UniversalWindows.csproj /t:Build /p:Configuration="Release"
+$vswhere = ${Env:\ProgramFiles(x86)} + '\Microsoft Visual Studio\Installer\vswhere'

-Remove-Item .\NuGet -Force -Recurse
-New-Item -ItemType Directory -Force -Path .\NuGet
-.\NuGet.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $version
+$path = &$vswhere -latest -products * -requires Microsoft.Component.MSBuild -property installationPath
+if ($path) {
+    $msbuild = join-path $path 'MSBuild\15.0\Bin\MSBuild.exe'
+
+	# Build the core library
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+    
+	# Build the ASP.NET Core 2.0 extension
+	&$msbuild ..\Frameworks\MQTTnet.AspNetCore\MQTTnet.AspNetCore.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+
+	# Build the RPC extension
+	&$msbuild ..\Extensions\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Extensions\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Extensions\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Extensions\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Extensions\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+
+    Remove-Item .\NuGet -Force -Recurse -ErrorAction SilentlyContinue
+
+    New-Item -ItemType Directory -Force -Path .\NuGet
+    .\NuGet.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+    .\NuGet.exe pack MQTTnet.AspNetCore.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+	.\NuGet.exe pack MQTTnet.Extensions.Rpc.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+}
@@ -0,0 +1,9 @@
+# Import codeSigningKey.pfx
+In order to import the key for code signing on a new developer machine use the following command within the VS developer command line:
+
+> sn –i codeSigningKey.pfx VS_KEY_EFCA4C5B6DFD4B4F
+
+The container name may be different.
+
+# Check if the assembly has a strong name
+> sn -vf MQTTnet.dll
@@ -0,0 +1,31 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;net452;net461;uap10.0</TargetFrameworks>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+    <FileVersion>0.0.0.0</FileVersion>
+    <Product />
+    <Company />
+    <Authors />
+    <PackageId />
+    <Version>0.0.0.0</Version>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
+    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
+    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
+    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
+    <TargetPlatformVersion>10.0.16299.0</TargetPlatformVersion>
+    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
+    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
+    <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
+    <DefaultLanguage>en</DefaultLanguage>
+    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\Frameworks\MQTTnet.Netstandard\MQTTnet.NetStandard.csproj" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Concurrent;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Internal;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Extensions.Rpc
+{
+    public sealed class MqttRpcClient : IDisposable
+    {
+        private const string ResponseTopic = "$MQTTnet.RPC/+/+/response";
+        private readonly ConcurrentDictionary<string, TaskCompletionSource<byte[]>> _waitingCalls = new ConcurrentDictionary<string, TaskCompletionSource<byte[]>>();
+        private readonly IMqttClient _mqttClient;
+        private bool _isEnabled;
+
+        public MqttRpcClient(IMqttClient mqttClient)
+        {
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            _mqttClient.ApplicationMessageReceived += OnApplicationMessageReceived;
+        }
+
+        public async Task EnableAsync()
+        {
+            await _mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(ResponseTopic).WithAtLeastOnceQoS().Build());
+            _isEnabled = true;
+        }
+
+        public async Task DisableAsync()
+        {
+            await _mqttClient.UnsubscribeAsync(ResponseTopic);
+            _isEnabled = false;
+        }
+
+        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            if (methodName == null) throw new ArgumentNullException(nameof(methodName));
+
+            if (methodName.Contains("/") || methodName.Contains("+") || methodName.Contains("#"))
+            {
+                throw new ArgumentException("The method name cannot contain /, + or #.");
+            }
+
+            if (!_isEnabled)
+            {
+                throw new InvalidOperationException("The RPC client is not enabled.");
+            }
+
+            var requestTopic = $"$MQTTnet.RPC/{Guid.NewGuid():N}/{methodName}";
+            var responseTopic = requestTopic + "/response";
+
+            var requestMessage = new MqttApplicationMessageBuilder()
+                .WithTopic(requestTopic)
+                .WithPayload(payload)
+                .WithQualityOfServiceLevel(qualityOfServiceLevel)
+                .Build();
+
+            try
+            {
+                var tcs = new TaskCompletionSource<byte[]>();
+                if (!_waitingCalls.TryAdd(responseTopic, tcs))
+                {
+                    throw new InvalidOperationException();
+                }
+
+                await _mqttClient.PublishAsync(requestMessage);
+                return await tcs.Task.TimeoutAfter(timeout);
+            }
+            finally
+            {
+                _waitingCalls.TryRemove(responseTopic, out _);
+            }
+        }
+
+        private void OnApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs eventArgs)
+        {
+            if (!_waitingCalls.TryRemove(eventArgs.ApplicationMessage.Topic, out TaskCompletionSource<byte[]> tcs))
+            {
+                return;
+            }
+
+            if (tcs.Task.IsCompleted || tcs.Task.IsCanceled)
+            {
+                return;
+            }
+
+            tcs.TrySetResult(eventArgs.ApplicationMessage.Payload);
+        }
+
+        public void Dispose()
+        {
+            foreach (var tcs in _waitingCalls)
+            {
+                tcs.Value.SetCanceled();
+            }
+
+            _waitingCalls.Clear();
+        }
+    }
+}
@@ -0,0 +1 @@
+
@@ -0,0 +1,52 @@
+using System;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using System.Linq;
+using MQTTnet.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class ApplicationBuilderExtensions
+    {
+        public static IApplicationBuilder UseMqttEndpoint(this IApplicationBuilder app, string path = "/mqtt")
+        {
+            app.UseWebSockets();
+            app.Use(async (context, next) =>
+            {
+                if (context.Request.Path == path && context.WebSockets.IsWebSocketRequest)
+                {
+                    string subprotocol = null;
+
+                    if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues)
+                     && requestedSubProtocolValues.Count > 0
+                     && requestedSubProtocolValues.Any(v => v.ToLower() == "mqtt")
+                     )
+                    {
+                        subprotocol = "mqtt";
+                    }
+
+                    var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
+                    using (var webSocket = await context.WebSockets.AcceptWebSocketAsync(subprotocol))
+                    {
+                        await adapter.AcceptWebSocketAsync(webSocket);
+                    }
+                }
+                else
+                {
+                    await next();
+                }
+            });
+
+            return app;
+        }
+
+        public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<IMqttServer> configure)
+        {
+            var server = app.ApplicationServices.GetRequiredService<IMqttServer>();
+
+            configure(server);
+
+            return app;
+        }
+    }
+}
@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+    <FileVersion>0.0.0.0</FileVersion>
+    <Version>0.0.0.0</Version>
+    <Product />
+    <Company />
+    <Authors />
+    <PackageId />
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.0.1" />
+    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="2.0.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\MQTTnet.Netstandard\MQTTnet.NetStandard.csproj" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Hosting;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public class MqttHostedServer : MqttServer, IHostedService
+    {
+        private readonly IMqttServerOptions _options;
+
+        public MqttHostedServer(IMqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) : base(adapters, logger)
+        {
+            _options = options ?? throw new ArgumentNullException(nameof(options));
+        }
+
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            return StartAsync(_options);
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            return StopAsync();
+        }
+    }
+}
@@ -0,0 +1,42 @@
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Serializer;
+using MQTTnet.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter, IDisposable
+    {
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public Task StartAsync(IMqttServerOptions options)
+        {
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync()
+        {
+            return Task.CompletedTask;
+        }
+
+        public Task AcceptWebSocketAsync(WebSocket webSocket)
+        {
+            if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));
+
+            var channel = new MqttWebSocketServerChannel(webSocket);
+            var clientAdapter = new MqttChannelAdapter(channel, new MqttPacketSerializer(), new MqttNetLogger());
+
+            var eventArgs = new MqttServerAdapterClientAcceptedEventArgs(clientAdapter);
+            ClientAccepted?.Invoke(this, eventArgs);
+            return eventArgs.SessionTask;
+        }
+        
+        public void Dispose()
+        {
+            StopAsync();
+        }
+    }
+}
@@ -0,0 +1,60 @@
+using System;
+using System.IO;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Channel;
+using MQTTnet.Implementations;
+
+namespace MQTTnet.AspNetCore
+{
+    public class MqttWebSocketServerChannel : IMqttChannel, IDisposable
+    {
+        private WebSocket _webSocket;
+
+        public MqttWebSocketServerChannel(WebSocket webSocket)
+        {
+            _webSocket = webSocket ?? throw new ArgumentNullException(nameof(webSocket));
+
+            SendStream = new WebSocketStream(_webSocket);
+            ReceiveStream = SendStream;
+        }
+
+        public Stream SendStream { get; private set; }
+        public Stream ReceiveStream { get; private set; }
+
+        public Task ConnectAsync()
+        {
+            return Task.CompletedTask;
+        }
+
+        public async Task DisconnectAsync()
+        {
+            if (_webSocket == null)
+            {
+                return;
+            }
+
+            try
+            {
+                await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None);
+            }
+            finally
+            {
+                Dispose();
+            }
+        }
+
+        public void Dispose()
+        {
+            SendStream?.Dispose();
+            ReceiveStream?.Dispose();
+
+            _webSocket?.Dispose();
+
+            SendStream = null;
+            ReceiveStream = null;
+            _webSocket = null;
+        }
+    }
+}
@@ -0,0 +1,31 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Server;
+using MQTTnet.Implementations;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class ServiceCollectionExtensions
+    {
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, IMqttServerOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            services.AddSingleton(options);
+            services.AddSingleton<IMqttNetLogger>(new MqttNetLogger());
+            services.AddSingleton<MqttHostedServer>();
+            services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
+            services.AddSingleton<IMqttServer>(s => s.GetService<MqttHostedServer>());
+            
+            services.AddSingleton<MqttWebSocketServerAdapter>();
+            services.AddSingleton<MqttTcpServerAdapter>();
+            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttWebSocketServerAdapter>()); 
+            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttTcpServerAdapter>());
+
+            return services;
+        }
+    }
+}
@@ -1,27 +0,0 @@
-using System;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet.Implementations
-{
-    public class MqttCommunicationAdapterFactory : IMqttCommunicationAdapterFactory
-    {
-        public IMqttCommunicationAdapter CreateMqttCommunicationAdapter(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            if (options is MqttClientTcpOptions tcpOptions)
-            {
-                return new MqttChannelCommunicationAdapter(new MqttTcpChannel(tcpOptions), new MqttPacketSerializer { ProtocolVersion = options.ProtocolVersion });
-            }
-
-            if (options is MqttClientWebSocketOptions webSocketOptions)
-            {
-                return new MqttChannelCommunicationAdapter(new MqttWebSocketChannel(webSocketOptions), new MqttPacketSerializer { ProtocolVersion = options.ProtocolVersion });
-            }
-
-            throw new NotSupportedException();
-        }
-    }
-}
@@ -1,133 +0,0 @@
-using System;
-using System.Net;
-using System.Net.Security;
-using System.Net.Sockets;
-using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Diagnostics;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet.Implementations
-{
-    public class MqttServerAdapter : IMqttServerAdapter, IDisposable
-    {
-        private CancellationTokenSource _cancellationTokenSource;
-        private Socket _defaultEndpointSocket;
-        private Socket _tlsEndpointSocket;
-        private X509Certificate2 _tlsCertificate;
-
-        private bool _isRunning;
-
-        public event Action<IMqttCommunicationAdapter> ClientAccepted;
-
-        public Task StartAsync(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            if (_isRunning) throw new InvalidOperationException("Server is already started.");
-            _isRunning = true;
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            if (options.DefaultEndpointOptions.IsEnabled)
-            {
-                _defaultEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-                _defaultEndpointSocket.Bind(new IPEndPoint(IPAddress.Any, options.GetDefaultEndpointPort()));
-                _defaultEndpointSocket.Listen(options.ConnectionBacklog);
-
-                Task.Run(() => AcceptDefaultEndpointConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-            }
-
-            if (options.TlsEndpointOptions.IsEnabled)
-            {
-                if (options.TlsEndpointOptions.Certificate == null)
-                {
-                    throw new ArgumentException("TLS certificate is not set.");
-                }
-
-                _tlsCertificate = new X509Certificate2(options.TlsEndpointOptions.Certificate);
-
-                _tlsEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-                _tlsEndpointSocket.Bind(new IPEndPoint(IPAddress.Any, options.GetTlsEndpointPort()));
-                _tlsEndpointSocket.Listen(options.ConnectionBacklog);
-
-                Task.Run(() => AcceptTlsEndpointConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-            }
-
-            return Task.FromResult(0);
-        }
-
-        public Task StopAsync()
-        {
-            _isRunning = false;
-
-            _cancellationTokenSource?.Cancel(false);
-            _cancellationTokenSource?.Dispose();
-            _cancellationTokenSource = null;
-
-            _defaultEndpointSocket?.Dispose();
-            _defaultEndpointSocket = null;
-
-            _tlsEndpointSocket?.Dispose();
-            _tlsEndpointSocket = null;
-
-            return Task.FromResult(0);
-        }
-
-        public void Dispose()
-        {
-            StopAsync();
-        }
-
-        private async Task AcceptDefaultEndpointConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                try
-                {
-                    var clientSocket = await Task.Factory.FromAsync(_defaultEndpointSocket.BeginAccept, _defaultEndpointSocket.EndAccept, null).ConfigureAwait(false);
-
-                    var tcpChannel = new MqttTcpChannel(clientSocket, null);
-                    var clientAdapter = new MqttChannelCommunicationAdapter(tcpChannel, new MqttPacketSerializer());
-                    ClientAccepted?.Invoke(clientAdapter);
-                }
-                catch (Exception exception) when (!(exception is ObjectDisposedException))
-                {
-                    MqttNetTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at default endpoint.");
-
-                    //excessive CPU consumed if in endless loop of socket errors
-                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
-                }
-            }
-        }
-
-        private async Task AcceptTlsEndpointConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                try
-                {
-                    var clientSocket = await Task.Factory.FromAsync(_tlsEndpointSocket.BeginAccept, _tlsEndpointSocket.EndAccept, null).ConfigureAwait(false);
-
-                    var sslStream = new SslStream(new NetworkStream(clientSocket));
-                    await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
-
-                    var tcpChannel = new MqttTcpChannel(clientSocket, sslStream);
-                    var clientAdapter = new MqttChannelCommunicationAdapter(tcpChannel, new MqttPacketSerializer());
-                    ClientAccepted?.Invoke(clientAdapter);
-                }
-                catch (Exception exception)
-                {
-                    MqttNetTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at TLS endpoint.");
-
-                    //excessive CPU consumed if in endless loop of socket errors
-                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
-                }
-            }
-        }
-    }
-}
@@ -1,150 +0,0 @@
-using System;
-using System.Net.Security;
-using System.Net.Sockets;
-using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading.Tasks;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using System.IO;
-using System.Linq;
-
-namespace MQTTnet.Implementations
-{
-    public sealed class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
-    {
-        private readonly MqttClientTcpOptions _options;
-
-        // ReSharper disable once MemberCanBePrivate.Global
-        // ReSharper disable once AutoPropertyCanBeMadeGetOnly.Global
-        public static int BufferSize { get; set; } = 4096 * 20; // Can be changed for fine tuning by library user.
-
-        private Socket _socket;
-        private SslStream _sslStream;
-
-        /// <summary>
-        /// called on client sockets are created in connect
-        /// </summary>
-        public MqttTcpChannel(MqttClientTcpOptions options)
-        {
-            _options = options ?? throw new ArgumentNullException(nameof(options));
-        }
-
-        /// <summary>
-        /// called on server, sockets are passed in
-        /// connect will not be called
-        /// </summary>
-        public MqttTcpChannel(Socket socket, SslStream sslStream)
-        {
-            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
-            _sslStream = sslStream;
-
-            CreateStreams(socket, sslStream);
-        }
-
-        public Stream SendStream { get; private set; }
-        public Stream ReceiveStream { get; private set; }
-        public Stream RawReceiveStream { get; private set; }
-
-        public static Func<X509Certificate, X509Chain, SslPolicyErrors, MqttClientTcpOptions, bool> CustomCertificateValidationCallback { get; set; }
-
-        public async Task ConnectAsync()
-        {
-            if (_socket == null)
-            {
-                _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-            }
-
-            await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, _options.Server, _options.GetPort(), null).ConfigureAwait(false);
-
-            if (_options.TlsOptions.UseTls)
-            {
-                _sslStream = new SslStream(new NetworkStream(_socket, true), false, InternalUserCertificateValidationCallback);
-                await _sslStream.AuthenticateAsClientAsync(_options.Server, LoadCertificates(_options), SslProtocols.Tls12, _options.TlsOptions.IgnoreCertificateRevocationErrors).ConfigureAwait(false);
-            }
-
-            CreateStreams(_socket, _sslStream);
-        }
-
-        public Task DisconnectAsync()
-        {
-            Dispose();
-            return Task.FromResult(0);
-        }
-
-        public void Dispose()
-        {
-            RawReceiveStream?.Dispose();
-            RawReceiveStream = null;
-
-            ReceiveStream?.Dispose();
-            ReceiveStream = null;
-
-            SendStream?.Dispose();
-            SendStream = null;
-
-            _socket?.Dispose();
-            _socket = null;
-
-            _sslStream?.Dispose();
-            _sslStream = null;
-        }
-
-        private void CreateStreams(Socket socket, Stream sslStream)
-        {
-            RawReceiveStream = sslStream ?? new NetworkStream(socket);
-
-            //cannot use this as default buffering prevents from receiving the first connect message
-            //need two streams otherwise read and write have to be synchronized
-            SendStream = new BufferedStream(RawReceiveStream, BufferSize);
-            ReceiveStream = new BufferedStream(RawReceiveStream, BufferSize);
-        }
-
-        private bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
-        {
-            if (CustomCertificateValidationCallback != null)
-            {
-                return CustomCertificateValidationCallback(x509Certificate, chain, sslPolicyErrors, _options);
-            }
-
-            if (sslPolicyErrors == SslPolicyErrors.None)
-            {
-                return true;
-            }
-
-            if (chain.ChainStatus.Any(c => c.Status == X509ChainStatusFlags.RevocationStatusUnknown || c.Status == X509ChainStatusFlags.Revoked || c.Status == X509ChainStatusFlags.RevocationStatusUnknown))
-            {
-                if (!_options.TlsOptions.IgnoreCertificateRevocationErrors)
-                {
-                    return false;
-                }
-            }
-
-            if (chain.ChainStatus.Any(c => c.Status == X509ChainStatusFlags.PartialChain))
-            {
-                if (!_options.TlsOptions.IgnoreCertificateChainErrors)
-                {
-                    return false;
-                }
-            }
-            
-            return _options.TlsOptions.AllowUntrustedCertificates;
-        }
-
-        private static X509CertificateCollection LoadCertificates(MqttClientOptions options)
-        {
-            var certificates = new X509CertificateCollection();
-            if (options.TlsOptions.Certificates == null)
-            {
-                return certificates;
-            }
-
-            foreach (var certificate in options.TlsOptions.Certificates)
-            {
-                certificates.Add(new X509Certificate(certificate));
-            }
-
-            return certificates;
-        }
-    }
-}
@@ -1,57 +0,0 @@
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using System;
-using System.IO;
-using System.Net.WebSockets;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Implementations
-{
-    public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
-    {
-        private readonly MqttClientWebSocketOptions _options;
-
-        private ClientWebSocket _webSocket;
-
-        public MqttWebSocketChannel(MqttClientWebSocketOptions options)
-        {
-            _options = options ?? throw new ArgumentNullException(nameof(options));
-        }
-
-        public Stream RawReceiveStream { get; private set; }
-        public Stream SendStream => RawReceiveStream;
-        public Stream ReceiveStream => RawReceiveStream;
-        
-        public async Task ConnectAsync()
-        {
-            var uri = _options.Uri;
-            if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase))
-            {
-                uri = "ws://" + uri;
-            }
- 
-            _webSocket = new ClientWebSocket();
-            _webSocket.Options.KeepAliveInterval = _options.KeepAlivePeriod;
-            await _webSocket.ConnectAsync(new Uri(uri), CancellationToken.None).ConfigureAwait(false);
-            RawReceiveStream = new WebSocketStream(_webSocket);
-        }
-
-        public async Task DisconnectAsync()
-        {
-            RawReceiveStream = null;
-
-            if (_webSocket == null)
-            {
-                return;
-            }
-
-            await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
-        }
-
-        public void Dispose()
-        {
-            _webSocket?.Dispose();
-        }
-    }
-}
@@ -1,77 +0,0 @@
-using System;
-using System.IO;
-using System.Net.WebSockets;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Implementations
-{
-    public class WebSocketStream : Stream
-    {
-        private readonly ClientWebSocket _webSocket;
-
-        public WebSocketStream(ClientWebSocket webSocket)
-        {
-            _webSocket = webSocket;
-        }
-
-        public override void Flush()
-        {
-        }
-
-        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        {
-            var currentOffset = offset;
-            var targetOffset = offset + count;
-            while (_webSocket.State == WebSocketState.Open && currentOffset < targetOffset)
-            {
-                var response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer, currentOffset, count), cancellationToken).ConfigureAwait(false);
-                currentOffset += response.Count;
-
-                if (response.MessageType == WebSocketMessageType.Close)
-                {
-                    await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, cancellationToken).ConfigureAwait(false);
-                }
-            }
-
-            return currentOffset - offset;
-        }
-
-        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        {
-            return _webSocket.SendAsync(new ArraySegment<byte>(buffer, offset, count), WebSocketMessageType.Binary, true, cancellationToken);
-        }
-
-        public override int Read(byte[] buffer, int offset, int count)
-        {
-            return ReadAsync(buffer, offset, count).GetAwaiter().GetResult();
-        }
-
-        public override void Write(byte[] buffer, int offset, int count)
-        {
-            WriteAsync(buffer, offset, count).GetAwaiter().GetResult();
-        }
-
-        public override bool CanRead => true;
-        public override bool CanSeek => false;
-        public override bool CanWrite => true;
-
-        public override long Length => throw new NotSupportedException();
-
-        public override long Position
-        {
-            get => throw new NotSupportedException();
-            set => throw new NotSupportedException();
-        }
-
-        public override long Seek(long offset, SeekOrigin origin)
-        {
-            throw new NotSupportedException();
-        }
-
-        public override void SetLength(long value)
-        {
-            throw new NotSupportedException();
-        }
-    }
-}
@@ -1,126 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{A480EF90-0EAA-4D9A-B271-47A9C47F6F7D}</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>MQTTnet</RootNamespace>
-    <AssemblyName>MQTTnet</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <Prefer32Bit>false</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <Prefer32Bit>false</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Any CPU|AnyCPU'">
-    <OutputPath>bin\Any CPU\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <Optimize>true</Optimize>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
-    <DebugSymbols>true</DebugSymbols>
-    <OutputPath>bin\x86\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <DebugType>full</DebugType>
-    <PlatformTarget>x86</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
-    <OutputPath>bin\x86\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <Optimize>true</Optimize>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x86</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Any CPU|x86'">
-    <OutputPath>bin\x86\Any CPU\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <Optimize>true</Optimize>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x86</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
-    <DebugSymbols>true</DebugSymbols>
-    <OutputPath>bin\x64\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <DebugType>full</DebugType>
-    <PlatformTarget>x64</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
-    <OutputPath>bin\x64\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <Optimize>true</Optimize>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x64</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Any CPU|x64'">
-    <OutputPath>bin\x64\Any CPU\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <Optimize>true</Optimize>
-    <DebugType>pdbonly</DebugType>
-    <PlatformTarget>x64</PlatformTarget>
-    <ErrorReport>prompt</ErrorReport>
-    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="Implementations\MqttCommunicationAdapterFactory.cs" />
-    <Compile Include="Implementations\MqttWebSocketChannel.cs" />
-    <Compile Include="Implementations\WebSocketStream.cs" />
-    <Compile Include="MqttClientFactory.cs" />
-    <Compile Include="MqttServerFactory.cs" />
-    <Compile Include="Implementations\MqttServerAdapter.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="Implementations\MqttTcpChannel.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\..\MQTTnet.Core\MQTTnet.Core.csproj">
-      <Project>{2ecb99e4-72d0-4c23-99ba-93d511d3967d}</Project>
-      <Name>MQTTnet.Core</Name>
-    </ProjectReference>
-  </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
@@ -1,13 +0,0 @@
-using MQTTnet.Core.Client;
-using MQTTnet.Implementations;
-
-namespace MQTTnet
-{
-    public class MqttClientFactory : IMqttClientFactory
-    {
-        public IMqttClient CreateMqttClient()
-        {
-            return new MqttClient(new MqttCommunicationAdapterFactory());
-        }
-    }
-}
@@ -1,18 +0,0 @@
-using System;
-using System.Collections.Generic;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Server;
-using MQTTnet.Implementations;
-
-namespace MQTTnet
-{
-    public class MqttServerFactory : IMqttServerFactory
-    {
-        public IMqttServer CreateMqttServer(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttServer(options, new List<IMqttServerAdapter> { new MqttServerAdapter() });
-        }
-    }
-}
@@ -1,15 +0,0 @@
-using System.Reflection;
-using System.Runtime.InteropServices;
-
-[assembly: AssemblyTitle("MQTTnet")]
-[assembly: AssemblyDescription("MQTTnet for .NET Framework")]
-[assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("Christian Kratky")]
-[assembly: AssemblyProduct("MQTTnet")]
-[assembly: AssemblyCopyright("Copyright © Christian Kratky 2016-2017")]
-[assembly: AssemblyTrademark("")]
-[assembly: AssemblyCulture("")]
-[assembly: ComVisible(false)]
-[assembly: Guid("a480ef90-0eaa-4d9a-b271-47a9c47f6f7d")]
-[assembly: AssemblyVersion("2.4.0.0")]
-[assembly: AssemblyFileVersion("2.4.0.0")]
@@ -2,12 +2,12 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Core.Packets;
-using MQTTnet.Core.Serializer;
+using MQTTnet.Packets;
+using MQTTnet.Serializer;

-namespace MQTTnet.Core.Adapter
+namespace MQTTnet.Adapter
 {
-    public interface IMqttCommunicationAdapter
+    public interface IMqttChannelAdapter : IDisposable
    {
        IMqttPacketSerializer PacketSerializer { get; }

@@ -0,0 +1,14 @@
+using System;
+using System.Threading.Tasks;
+using MQTTnet.Server;
+
+namespace MQTTnet.Adapter
+{
+    public interface IMqttServerAdapter
+    {
+        event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        Task StartAsync(IMqttServerOptions options);
+        Task StopAsync();
+    }
+}
@@ -0,0 +1,255 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Channel;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.Adapter
+{
+    public sealed class MqttChannelAdapter : IMqttChannelAdapter
+    {
+        private const uint ErrorOperationAborted = 0x800703E3;
+        private const int ReadBufferSize = 4096;  // TODO: Move buffer size to config
+
+        private bool _isDisposed;
+        private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);
+        private readonly IMqttNetLogger _logger;
+        private readonly IMqttChannel _channel;
+
+        public MqttChannelAdapter(IMqttChannel channel, IMqttPacketSerializer serializer, IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            _channel = channel ?? throw new ArgumentNullException(nameof(channel));
+            PacketSerializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
+        }
+
+        public IMqttPacketSerializer PacketSerializer { get; }
+
+        public Task ConnectAsync(TimeSpan timeout)
+        {
+            ThrowIfDisposed();
+            _logger.Verbose<MqttChannelAdapter>("Connecting [Timeout={0}]", timeout);
+
+            return ExecuteAndWrapExceptionAsync(() => _channel.ConnectAsync().TimeoutAfter(timeout));
+        }
+
+        public Task DisconnectAsync(TimeSpan timeout)
+        {
+            ThrowIfDisposed();
+            _logger.Verbose<MqttChannelAdapter>("Disconnecting [Timeout={0}]", timeout);
+
+            return ExecuteAndWrapExceptionAsync(() => _channel.DisconnectAsync().TimeoutAfter(timeout));
+        }
+
+        public Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, IEnumerable<MqttBasePacket> packets)
+        {
+            ThrowIfDisposed();
+
+            return ExecuteAndWrapExceptionAsync(async () =>
+            {
+                await _semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
+                try
+                {
+                    foreach (var packet in packets)
+                    {
+                        if (cancellationToken.IsCancellationRequested)
+                        {
+                            return;
+                        }
+
+                        if (packet == null)
+                        {
+                            continue;
+                        }
+
+                        _logger.Verbose<MqttChannelAdapter>("TX >>> {0} [Timeout={1}]", packet, timeout);
+
+                        var chunks = PacketSerializer.Serialize(packet);
+                        foreach (var chunk in chunks)
+                        {
+                            if (cancellationToken.IsCancellationRequested)
+                            {
+                                return;
+                            }
+
+                            await _channel.SendStream.WriteAsync(chunk.Array, chunk.Offset, chunk.Count, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        return;
+                    }
+
+                    if (timeout > TimeSpan.Zero)
+                    {
+                        await _channel.SendStream.FlushAsync(cancellationToken).TimeoutAfter(timeout).ConfigureAwait(false);
+                    }
+                    else
+                    {
+                        await _channel.SendStream.FlushAsync(cancellationToken).ConfigureAwait(false);
+                    }
+                }
+                finally
+                {
+                    _semaphore.Release();
+                }
+            });
+        }
+
+        public async Task<MqttBasePacket> ReceivePacketAsync(TimeSpan timeout, CancellationToken cancellationToken)
+        {
+            ThrowIfDisposed();
+
+            MqttBasePacket packet = null;
+            await ExecuteAndWrapExceptionAsync(async () =>
+            {
+                ReceivedMqttPacket receivedMqttPacket = null;
+                try
+                {
+                    if (timeout > TimeSpan.Zero)
+                    {
+                        receivedMqttPacket = await ReceiveAsync(_channel.ReceiveStream, cancellationToken).TimeoutAfter(timeout).ConfigureAwait(false);
+                    }
+                    else
+                    {
+                        receivedMqttPacket = await ReceiveAsync(_channel.ReceiveStream, cancellationToken).ConfigureAwait(false);
+                    }
+
+                    if (receivedMqttPacket == null || cancellationToken.IsCancellationRequested)
+                    {
+                        throw new TaskCanceledException();
+                    }
+
+                    packet = PacketSerializer.Deserialize(receivedMqttPacket.Header, receivedMqttPacket.Body);
+                    if (packet == null)
+                    {
+                        throw new MqttProtocolViolationException("Received malformed packet.");
+                    }
+
+                    _logger.Verbose<MqttChannelAdapter>("RX <<< {0}", packet);
+                }
+                finally
+                {
+                    receivedMqttPacket?.Dispose();
+                }
+            }).ConfigureAwait(false);
+
+            return packet;
+        }
+
+        private static async Task<ReceivedMqttPacket> ReceiveAsync(Stream stream, CancellationToken cancellationToken)
+        {
+            var header = await MqttPacketReader.ReadHeaderAsync(stream, cancellationToken).ConfigureAwait(false);
+            if (header == null)
+            {
+                return null;
+            }
+
+            if (header.BodyLength == 0)
+            {
+                return new ReceivedMqttPacket(header, new MemoryStream(new byte[0], false));
+            }
+
+            var body = header.BodyLength <= ReadBufferSize ? new MemoryStream(header.BodyLength) : new MemoryStream();
+
+            var buffer = new byte[ReadBufferSize];
+            while (body.Length < header.BodyLength)
+            {
+                var bytesLeft = header.BodyLength - (int)body.Length;
+                if (bytesLeft > buffer.Length)
+                {
+                    bytesLeft = buffer.Length;
+                }
+
+                var readBytesCount = await stream.ReadAsync(buffer, 0, bytesLeft, cancellationToken).ConfigureAwait(false);
+
+                // Check if the client closed the connection before sending the full body.
+                if (readBytesCount == 0)
+                {
+                    throw new MqttCommunicationException("Connection closed while reading remaining packet body.");
+                }
+
+                // Here is no need to await because internally only an array is used and no real I/O operation is made.
+                // Using async here will only generate overhead.
+                body.Write(buffer, 0, readBytesCount);
+            }
+
+            body.Seek(0L, SeekOrigin.Begin);
+
+            return new ReceivedMqttPacket(header, body);
+        }
+
+        private static async Task ExecuteAndWrapExceptionAsync(Func<Task> action)
+        {
+            try
+            {
+                await action().ConfigureAwait(false);
+            }
+            catch (TaskCanceledException)
+            {
+                throw;
+            }
+            catch (OperationCanceledException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationTimedOutException)
+            {
+                throw;
+            }
+            catch (MqttCommunicationException)
+            {
+                throw;
+            }
+            catch (COMException comException)
+            {
+                if ((uint)comException.HResult == ErrorOperationAborted)
+                {
+                    throw new OperationCanceledException();
+                }
+
+                throw new MqttCommunicationException(comException);
+            }
+            catch (IOException exception)
+            {
+                if (exception.InnerException is SocketException socketException)
+                {
+                    if (socketException.SocketErrorCode == SocketError.ConnectionAborted)
+                    {
+                        throw new OperationCanceledException();
+                    }
+                }
+
+                throw new MqttCommunicationException(exception);
+            }
+            catch (Exception exception)
+            {
+                throw new MqttCommunicationException(exception);
+            }
+        }
+
+        public void Dispose()
+        {
+            _isDisposed = true;
+            _semaphore?.Dispose();
+            _channel?.Dispose();
+        }
+
+        private void ThrowIfDisposed()
+        {
+            if (_isDisposed)
+            {
+                throw new ObjectDisposedException(nameof(MqttChannelAdapter));
+            }
+        }
+    }
+}
@@ -1,7 +1,7 @@
-using MQTTnet.Core.Exceptions;
-using MQTTnet.Core.Protocol;
+using MQTTnet.Exceptions;
+using MQTTnet.Protocol;

-namespace MQTTnet.Core.Adapter
+namespace MQTTnet.Adapter
 {
    public class MqttConnectingFailedException : MqttCommunicationException
    {
@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Adapter
+{
+    public class MqttServerAdapterClientAcceptedEventArgs : EventArgs
+    {
+        public MqttServerAdapterClientAcceptedEventArgs(IMqttChannelAdapter client)
+        {
+            Client = client ?? throw new ArgumentNullException(nameof(client));
+        }
+
+        public IMqttChannelAdapter Client { get; }
+
+        public Task SessionTask { get; set; }
+    }
+}
@@ -1,10 +1,10 @@
 using System;
 using System.IO;
-using MQTTnet.Core.Packets;
+using MQTTnet.Packets;

-namespace MQTTnet.Core.Adapter
+namespace MQTTnet.Adapter
 {
-    public class ReceivedMqttPacket
+    public sealed class ReceivedMqttPacket : IDisposable
    {
        public ReceivedMqttPacket(MqttPacketHeader header, MemoryStream body)
        {
@@ -15,5 +15,10 @@ namespace MQTTnet.Core.Adapter
        public MqttPacketHeader Header { get; }

        public MemoryStream Body { get; }
+
+        public void Dispose()
+        {
+            Body?.Dispose();
+        }
    }
 }
@@ -0,0 +1,41 @@
+using System;
+using System.Threading.Tasks;
+using MQTTnet.Protocol;
+
+namespace MQTTnet
+{
+    public static class ApplicationMessagePublisherExtensions
+    {
+        public static Task PublishAsync(this IApplicationMessagePublisher publisher, params MqttApplicationMessage[] applicationMessages)
+        {
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
+
+            return publisher.PublishAsync(applicationMessages);
+        }
+
+        public static Task PublishAsync(this IApplicationMessagePublisher publisher, string topic)
+        {
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+            
+            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).Build());
+        }
+
+        public static Task PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload)
+        {
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(payload).Build());
+        }
+
+        public static Task PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(payload).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+        }
+    }
+}
@@ -1,13 +1,13 @@
-using System.Threading.Tasks;
+using System;
 using System.IO;
+using System.Threading.Tasks;

-namespace MQTTnet.Core.Channel
+namespace MQTTnet.Channel
 {
-    public interface IMqttCommunicationChannel
+    public interface IMqttChannel : IDisposable
    {
        Stream SendStream { get; }
        Stream ReceiveStream { get; }
-        Stream RawReceiveStream { get; }

        Task ConnectAsync();
        Task DisconnectAsync();
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Client
+{
+    public interface IMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher, IDisposable
+    {
+        bool IsConnected { get; }
+
+        event EventHandler<MqttClientConnectedEventArgs> Connected;
+        event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+
+        Task<MqttClientConnectResult> ConnectAsync(IMqttClientOptions options);
+        Task DisconnectAsync();
+
+        Task<IList<MqttSubscribeResult>> SubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+        Task UnsubscribeAsync(IEnumerable<string> topics);
+    }
+}
@@ -0,0 +1,10 @@
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Client
+{
+    public interface IMqttClientAdapterFactory
+    {
+        IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger);
+    }
+}
@@ -0,0 +1,7 @@
+namespace MQTTnet.Client
+{
+    public interface IMqttClientChannelOptions
+    {
+        MqttClientTlsOptions TlsOptions { get; }
+    }
+}
@@ -0,0 +1,8 @@
+namespace MQTTnet.Client
+{
+    public interface IMqttClientCredentials
+    {
+        string Password { get; }
+        string Username { get; }
+    }
+}
@@ -0,0 +1,16 @@
+using MQTTnet.Diagnostics;
+using MQTTnet.ManagedClient;
+
+namespace MQTTnet.Client
+{
+    public interface IMqttClientFactory
+    {
+        IMqttClient CreateMqttClient();
+
+        IMqttClient CreateMqttClient(IMqttNetLogger logger);
+        
+        IManagedMqttClient CreateManagedMqttClient();
+
+        IManagedMqttClient CreateManagedMqttClient(IMqttNetLogger logger);
+    }
+}
@@ -0,0 +1,22 @@
+using System;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.Client
+{
+    public interface IMqttClientOptions
+    {
+        string ClientId { get; }
+
+        IMqttClientCredentials Credentials { get; }
+        bool CleanSession { get; }
+        MqttApplicationMessage WillMessage { get; }
+        
+        TimeSpan CommunicationTimeout { get; }
+        TimeSpan KeepAlivePeriod { get; }
+        TimeSpan? KeepAliveSendInterval { get; }
+
+        MqttProtocolVersion ProtocolVersion { get; }
+
+        IMqttClientChannelOptions ChannelOptions { get; }
+    }
+}
@@ -0,0 +1,516 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Client
+{
+    public class MqttClient : IMqttClient
+    {
+        private readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
+        private readonly Stopwatch _sendTracker = new Stopwatch();
+        private readonly SemaphoreSlim _disconnectLock = new SemaphoreSlim(1, 1);
+        private readonly IMqttClientAdapterFactory _adapterFactory;
+        private readonly MqttPacketDispatcher _packetDispatcher;
+        private readonly IMqttNetLogger _logger;
+
+        private IMqttClientOptions _options;
+        private bool _isReceivingPackets;
+        private CancellationTokenSource _cancellationTokenSource;
+        private Task _packetReceiverTask;
+        private Task _keepAliveMessageSenderTask;
+        private IMqttChannelAdapter _adapter;
+
+        public MqttClient(IMqttClientAdapterFactory channelFactory, IMqttNetLogger logger)
+        {
+            _adapterFactory = channelFactory ?? throw new ArgumentNullException(nameof(channelFactory));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+
+            _packetDispatcher = new MqttPacketDispatcher(logger);
+        }
+
+        public event EventHandler<MqttClientConnectedEventArgs> Connected;
+        public event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+        public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
+
+        public bool IsConnected { get; private set; }
+
+        public async Task<MqttClientConnectResult> ConnectAsync(IMqttClientOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+            if (options.ChannelOptions == null) throw new ArgumentException("ChannelOptions are not set.");
+
+            ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");
+
+            try
+            {
+                _options = options;
+                _cancellationTokenSource = new CancellationTokenSource();
+                _packetIdentifierProvider.Reset();
+                _packetDispatcher.Reset();
+
+                _adapter = _adapterFactory.CreateClientAdapter(options, _logger);
+
+                _logger.Verbose<MqttClient>("Trying to connect with server.");
+                await _adapter.ConnectAsync(_options.CommunicationTimeout).ConfigureAwait(false);
+                _logger.Verbose<MqttClient>("Connection with server established.");
+
+                await StartReceivingPacketsAsync().ConfigureAwait(false);
+
+                var connectResponse = await AuthenticateAsync(options.WillMessage).ConfigureAwait(false);
+                _logger.Verbose<MqttClient>("MQTT connection with server established.");
+
+                _sendTracker.Restart();
+
+                if (_options.KeepAlivePeriod != TimeSpan.Zero)
+                {
+                    StartSendingKeepAliveMessages();
+                }
+
+                IsConnected = true;
+                Connected?.Invoke(this, new MqttClientConnectedEventArgs(connectResponse.IsSessionPresent));
+
+                _logger.Info<MqttClient>("Connected.");
+                return new MqttClientConnectResult(connectResponse.IsSessionPresent);
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<MqttClient>(exception, "Error while connecting with server.");
+                await DisconnectInternalAsync(null, exception).ConfigureAwait(false);
+
+                throw;
+            }
+        }
+
+        public async Task DisconnectAsync()
+        {
+            if (!IsConnected)
+            {
+                return;
+            }
+
+            try
+            {
+                if (!_cancellationTokenSource.IsCancellationRequested)
+                {
+                    await SendAsync(new MqttDisconnectPacket()).ConfigureAwait(false);
+                }
+            }
+            finally
+            {
+                await DisconnectInternalAsync(null, null).ConfigureAwait(false);
+            }
+        }
+
+        public async Task<IList<MqttSubscribeResult>> SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
+        {
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            ThrowIfNotConnected();
+
+            var subscribePacket = new MqttSubscribePacket
+            {
+                PacketIdentifier = _packetIdentifierProvider.GetNewPacketIdentifier(),
+                TopicFilters = topicFilters.ToList()
+            };
+
+            var response = await SendAndReceiveAsync<MqttSubAckPacket>(subscribePacket).ConfigureAwait(false);
+
+            if (response.SubscribeReturnCodes.Count != subscribePacket.TopicFilters.Count)
+            {
+                throw new MqttProtocolViolationException("The return codes are not matching the topic filters [MQTT-3.9.3-1].");
+            }
+
+            return subscribePacket.TopicFilters.Select((t, i) => new MqttSubscribeResult(t, response.SubscribeReturnCodes[i])).ToList();
+        }
+
+        public async Task UnsubscribeAsync(IEnumerable<string> topicFilters)
+        {
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            ThrowIfNotConnected();
+
+            var unsubscribePacket = new MqttUnsubscribePacket
+            {
+                PacketIdentifier = _packetIdentifierProvider.GetNewPacketIdentifier(),
+                TopicFilters = topicFilters.ToList()
+            };
+
+            await SendAndReceiveAsync<MqttUnsubAckPacket>(unsubscribePacket).ConfigureAwait(false);
+        }
+
+        public async Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
+        {
+            ThrowIfNotConnected();
+
+            var publishPackets = applicationMessages.Select(m => m.ToPublishPacket());
+            var packetGroups = publishPackets.GroupBy(p => p.QualityOfServiceLevel).OrderBy(g => g.Key);
+
+            foreach (var qosGroup in packetGroups)
+            {
+                switch (qosGroup.Key)
+                {
+                    case MqttQualityOfServiceLevel.AtMostOnce:
+                        {
+                            // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
+                            await SendAsync(qosGroup.Cast<MqttBasePacket>().ToArray()).ConfigureAwait(false);
+                            break;
+                        }
+                    case MqttQualityOfServiceLevel.AtLeastOnce:
+                        {
+                            foreach (var publishPacket in qosGroup)
+                            {
+                                publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNewPacketIdentifier();
+                                await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket).ConfigureAwait(false);
+                            }
+
+                            break;
+                        }
+                    case MqttQualityOfServiceLevel.ExactlyOnce:
+                        {
+                            foreach (var publishPacket in qosGroup)
+                            {
+                                publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNewPacketIdentifier();
+
+                                var pubRecPacket = await SendAndReceiveAsync<MqttPubRecPacket>(publishPacket).ConfigureAwait(false);
+                                var pubRelPacket = new MqttPubRelPacket
+                                {
+                                    PacketIdentifier = pubRecPacket.PacketIdentifier
+                                };
+
+                                await SendAndReceiveAsync<MqttPubCompPacket>(pubRelPacket).ConfigureAwait(false);
+                            }
+
+                            break;
+                        }
+                    default:
+                        {
+                            throw new InvalidOperationException();
+                        }
+                }
+            }
+        }
+
+        public void Dispose()
+        {
+            _cancellationTokenSource?.Dispose();
+            _cancellationTokenSource = null;
+
+            _adapter?.Dispose();
+        }
+
+        private async Task<MqttConnAckPacket> AuthenticateAsync(MqttApplicationMessage willApplicationMessage)
+        {
+            var connectPacket = new MqttConnectPacket
+            {
+                ClientId = _options.ClientId,
+                Username = _options.Credentials?.Username,
+                Password = _options.Credentials?.Password,
+                CleanSession = _options.CleanSession,
+                KeepAlivePeriod = (ushort)_options.KeepAlivePeriod.TotalSeconds,
+                WillMessage = willApplicationMessage
+            };
+
+            var response = await SendAndReceiveAsync<MqttConnAckPacket>(connectPacket).ConfigureAwait(false);
+            if (response.ConnectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
+            {
+                throw new MqttConnectingFailedException(response.ConnectReturnCode);
+            }
+
+            return response;
+        }
+
+        private void ThrowIfNotConnected()
+        {
+            if (!IsConnected) throw new MqttCommunicationException("The client is not connected.");
+        }
+
+        private void ThrowIfConnected(string message)
+        {
+            if (IsConnected) throw new MqttProtocolViolationException(message);
+        }
+
+        private async Task DisconnectInternalAsync(Task sender, Exception exception)
+        {
+            await _disconnectLock.WaitAsync();
+            try
+            {
+                if (_cancellationTokenSource == null || _cancellationTokenSource.IsCancellationRequested)
+                {
+                    return;
+                }
+
+                _cancellationTokenSource.Cancel(false);
+            }
+            catch (Exception adapterException)
+            {
+                _logger.Warning<MqttClient>(adapterException, "Error while disconnecting from adapter.");
+            }
+            finally
+            {
+                _disconnectLock.Release();
+            }
+
+            var clientWasConnected = IsConnected;
+            IsConnected = false;
+
+            try
+            {
+                if (_packetReceiverTask != null && _packetReceiverTask != sender)
+                {
+                    _packetReceiverTask.Wait();
+                }
+
+                if (_keepAliveMessageSenderTask != null && _keepAliveMessageSenderTask != sender)
+                {
+                    _keepAliveMessageSenderTask.Wait();
+                }
+
+                if (_adapter != null)
+                {
+                    await _adapter.DisconnectAsync(_options.CommunicationTimeout).ConfigureAwait(false);
+                }
+                
+                _logger.Verbose<MqttClient>("Disconnected from adapter.");
+            }
+            catch (Exception adapterException)
+            {
+                _logger.Warning<MqttClient>(adapterException, "Error while disconnecting from adapter.");
+            }
+            finally
+            {
+                _adapter?.Dispose();
+                _adapter = null;
+                _cancellationTokenSource?.Dispose();
+                _cancellationTokenSource = null;
+
+                _logger.Info<MqttClient>("Disconnected.");
+                Disconnected?.Invoke(this, new MqttClientDisconnectedEventArgs(clientWasConnected, exception));
+            }
+        }
+
+        private async Task ProcessReceivedPacketAsync(MqttBasePacket packet)
+        {
+            try
+            {
+                if (packet is MqttPublishPacket publishPacket)
+                {
+                    await ProcessReceivedPublishPacketAsync(publishPacket).ConfigureAwait(false);
+                    return;
+                }
+
+                if (packet is MqttPingReqPacket)
+                {
+                    await SendAsync(new MqttPingRespPacket()).ConfigureAwait(false);
+                    return;
+                }
+
+                if (packet is MqttDisconnectPacket)
+                {
+                    await DisconnectAsync().ConfigureAwait(false);
+                    return;
+                }
+
+                if (packet is MqttPubRelPacket pubRelPacket)
+                {
+                    await ProcessReceivedPubRelPacket(pubRelPacket).ConfigureAwait(false);
+                    return;
+                }
+
+                _packetDispatcher.Dispatch(packet);
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<MqttClient>(exception, "Unhandled exception while processing received packet.");
+            }
+        }
+
+        private void FireApplicationMessageReceivedEvent(MqttPublishPacket publishPacket)
+        {
+            try
+            {
+                var applicationMessage = publishPacket.ToApplicationMessage();
+                ApplicationMessageReceived?.Invoke(this, new MqttApplicationMessageReceivedEventArgs(_options.ClientId, applicationMessage));
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<MqttClient>(exception, "Unhandled exception while handling application message.");
+            }
+        }
+
+        private Task ProcessReceivedPublishPacketAsync(MqttPublishPacket publishPacket)
+        {
+            if (_cancellationTokenSource.IsCancellationRequested)
+            {
+                return Task.FromResult(0);
+            }
+
+            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
+            {
+                FireApplicationMessageReceivedEvent(publishPacket);
+                return Task.FromResult(0);
+            }
+
+            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+            {
+                FireApplicationMessageReceivedEvent(publishPacket);
+                return SendAsync(new MqttPubAckPacket { PacketIdentifier = publishPacket.PacketIdentifier });
+            }
+
+            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+            {
+                // QoS 2 is implement as method "B" [4.3.3 QoS 2: Exactly once delivery]
+                FireApplicationMessageReceivedEvent(publishPacket);
+                return SendAsync(new MqttPubRecPacket { PacketIdentifier = publishPacket.PacketIdentifier });
+            }
+
+            throw new MqttCommunicationException("Received a not supported QoS level.");
+        }
+
+        private Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket)
+        {
+            var response = new MqttPubCompPacket
+            {
+                PacketIdentifier = pubRelPacket.PacketIdentifier
+            };
+
+            return SendAsync(response);
+        }
+
+        private Task SendAsync(params MqttBasePacket[] packets)
+        {
+            _sendTracker.Restart();
+            return _adapter.SendPacketsAsync(_options.CommunicationTimeout, _cancellationTokenSource.Token, packets);
+        }
+
+        private async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket) where TResponsePacket : MqttBasePacket
+        {
+            ushort? identifier = null;
+            if (requestPacket is IMqttPacketWithIdentifier requestPacketWithIdentifier)
+            {
+                identifier = requestPacketWithIdentifier.PacketIdentifier;
+            }
+
+            var packetAwaiter = _packetDispatcher.WaitForPacketAsync(typeof(TResponsePacket), identifier, _options.CommunicationTimeout);
+            await SendAsync(requestPacket).ConfigureAwait(false);
+
+            return (TResponsePacket)await packetAwaiter.ConfigureAwait(false);
+        }
+
+        private async Task SendKeepAliveMessagesAsync()
+        {
+            _logger.Verbose<MqttClient>("Start sending keep alive packets.");
+
+            try
+            {
+                while (!_cancellationTokenSource.Token.IsCancellationRequested)
+                {
+                    var keepAliveSendInterval = TimeSpan.FromSeconds(_options.KeepAlivePeriod.TotalSeconds * 0.75);
+                    if (_options.KeepAliveSendInterval.HasValue)
+                    {
+                        keepAliveSendInterval = _options.KeepAliveSendInterval.Value;
+                    }
+
+                    if (_sendTracker.Elapsed > keepAliveSendInterval)
+                    {
+                        await SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket()).ConfigureAwait(false);
+                    }
+
+                    await Task.Delay(keepAliveSendInterval, _cancellationTokenSource.Token).ConfigureAwait(false);
+                }
+            }
+            catch (Exception exception)
+            {
+                if (exception is OperationCanceledException)
+                {
+                }
+                else if (exception is MqttCommunicationException)
+                {
+                    _logger.Warning<MqttClient>(exception, "MQTT communication exception while sending/receiving keep alive packets.");
+                }
+                else
+                {
+                    _logger.Error<MqttClient>(exception, "Unhandled exception while sending/receiving keep alive packets.");
+                }
+                
+                await DisconnectInternalAsync(_keepAliveMessageSenderTask, exception).ConfigureAwait(false);
+            }
+            finally
+            {
+                _logger.Verbose<MqttClient>("Stopped sending keep alive packets.");
+            }
+        }
+
+        private async Task ReceivePacketsAsync()
+        {
+            _logger.Verbose<MqttClient>("Start receiving packets.");
+
+            try
+            {
+                while (!_cancellationTokenSource.Token.IsCancellationRequested)
+                {
+                    _isReceivingPackets = true;
+
+                    var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
+
+                    if (_cancellationTokenSource.Token.IsCancellationRequested)
+                    {
+                        return;
+                    }
+
+                    StartProcessReceivedPacket(packet);
+                }
+            }
+            catch (Exception exception)
+            {
+                if (exception is OperationCanceledException)
+                {
+                }
+                else if (exception is MqttCommunicationException)
+                {
+                    _logger.Warning<MqttClient>(exception, "MQTT communication exception while receiving packets.");
+                }
+                else
+                {
+                    _logger.Error<MqttClient>(exception, "Unhandled exception while receiving packets.");
+                }
+
+                await DisconnectInternalAsync(_packetReceiverTask, exception).ConfigureAwait(false);
+            }
+            finally
+            {
+                _logger.Verbose<MqttClient>("Stopped receiving packets.");
+            }
+        }
+
+        private void StartProcessReceivedPacket(MqttBasePacket packet)
+        {
+            Task.Run(() => ProcessReceivedPacketAsync(packet), _cancellationTokenSource.Token);
+        }
+
+        private async Task StartReceivingPacketsAsync()
+        {
+            _isReceivingPackets = false;
+
+            _packetReceiverTask = Task.Run(ReceivePacketsAsync, _cancellationTokenSource.Token);
+
+            while (!_isReceivingPackets && !_cancellationTokenSource.Token.IsCancellationRequested)
+            {
+                await Task.Delay(TimeSpan.FromMilliseconds(100), _cancellationTokenSource.Token).ConfigureAwait(false);
+            }
+        }
+
+        private void StartSendingKeepAliveMessages()
+        {
+            _keepAliveMessageSenderTask = Task.Run(SendKeepAliveMessagesAsync, _cancellationTokenSource.Token);
+        }
+    }
+}
@@ -0,0 +1,12 @@
+namespace MQTTnet.Client
+{
+    public class MqttClientConnectResult
+    {
+        public MqttClientConnectResult(bool isSessionPresent)
+        {
+            IsSessionPresent = isSessionPresent;
+        }
+
+        public bool IsSessionPresent { get; }
+    }
+}
@@ -0,0 +1,14 @@
+using System;
+
+namespace MQTTnet.Client
+{
+    public class MqttClientConnectedEventArgs : EventArgs
+    {
+        public MqttClientConnectedEventArgs(bool isSessionPresent)
+        {
+            IsSessionPresent = isSessionPresent;
+        }
+
+        public bool IsSessionPresent { get; }
+    }
+}
@@ -0,0 +1,9 @@
+namespace MQTTnet.Client
+{
+    public class MqttClientCredentials : IMqttClientCredentials
+    {
+        public string Username { get; set; }
+
+        public string Password { get; set; }
+    }
+}
@@ -0,0 +1,17 @@
+using System;
+
+namespace MQTTnet.Client
+{
+    public class MqttClientDisconnectedEventArgs : EventArgs
+    {
+        public MqttClientDisconnectedEventArgs(bool clientWasConnected, Exception exception)
+        {
+            ClientWasConnected = clientWasConnected;
+            Exception = exception;
+        }
+
+        public bool ClientWasConnected { get; }
+
+        public Exception Exception { get; }
+    }
+}
@@ -2,20 +2,12 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using MQTTnet.Core.Packets;
+using MQTTnet.Protocol;

-namespace MQTTnet.Core.Client
+namespace MQTTnet.Client
 {
    public static class MqttClientExtensions
    {
-        public static Task PublishAsync(this IMqttClient client, params MqttApplicationMessage[] applicationMessages)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
-
-            return client.PublishAsync(applicationMessages);
-        }
-
        public static Task<IList<MqttSubscribeResult>> SubscribeAsync(this IMqttClient client, params TopicFilter[] topicFilters)
        {
            if (client == null) throw new ArgumentNullException(nameof(client));
@@ -24,6 +16,22 @@ namespace MQTTnet.Core.Client
            return client.SubscribeAsync(topicFilters.ToList());
        }

+        public static Task<IList<MqttSubscribeResult>> SubscribeAsync(this IMqttClient client, string topic, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+        }
+
+        public static Task<IList<MqttSubscribeResult>> SubscribeAsync(this IMqttClient client, string topic)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).Build());
+        }
+
        public static Task UnsubscribeAsync(this IMqttClient client, params string[] topicFilters)
        {
            if (client == null) throw new ArgumentNullException(nameof(client));
@@ -0,0 +1,26 @@
+using System;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.Client
+{
+    public class MqttClientOptions : IMqttClientOptions
+    {
+        public MqttApplicationMessage WillMessage { get; set; }
+
+        public string ClientId { get; set; } = Guid.NewGuid().ToString("N");
+
+        public bool CleanSession { get; set; } = true;
+
+        public IMqttClientCredentials Credentials { get; set; } = new MqttClientCredentials();
+
+        public TimeSpan KeepAlivePeriod { get; set; } = TimeSpan.FromSeconds(15);
+
+        public TimeSpan? KeepAliveSendInterval { get; set; }
+
+        public TimeSpan CommunicationTimeout { get; set; } = TimeSpan.FromSeconds(10);
+
+        public MqttProtocolVersion ProtocolVersion { get; set; } = MqttProtocolVersion.V311;
+
+        public IMqttClientChannelOptions ChannelOptions { get; set; }
+    }
+}
@@ -0,0 +1,135 @@
+using System;
+using System.Linq;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.Client
+{
+    public class MqttClientOptionsBuilder
+    {
+        private readonly MqttClientOptions _options = new MqttClientOptions();
+        private MqttClientTcpOptions _tcpOptions;
+        private MqttClientWebSocketOptions _webSocketOptions;
+
+        private MqttClientTlsOptions _tlsOptions;
+
+        public MqttClientOptionsBuilder WithProtocolVersion(MqttProtocolVersion value)
+        {
+            _options.ProtocolVersion = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithCommunicationTimeout(TimeSpan value)
+        {
+            _options.CommunicationTimeout = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithCleanSession(bool value = true)
+        {
+            _options.CleanSession = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithKeepAlivePeriod(TimeSpan value)
+        {
+            _options.KeepAlivePeriod = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithClientId(string value)
+        {
+            _options.ClientId = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithWillMessage(MqttApplicationMessage value)
+        {
+            _options.WillMessage = value;
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithCredentials(string username, string password = null)
+        {
+            _options.Credentials = new MqttClientCredentials
+            {
+                Username = username,
+                Password = password
+            };
+
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithTcpServer(string server, int? port = null)
+        {
+            _tcpOptions = new MqttClientTcpOptions
+            {
+                Server = server,
+                Port = port
+            };
+
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithWebSocketServer(string uri)
+        {
+            _webSocketOptions = new MqttClientWebSocketOptions
+            {
+                Uri = uri
+            };
+
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithTls(
+            bool allowUntrustedCertificates = false,
+            bool ignoreCertificateChainErrors = false,
+            bool ignoreCertificateRevocationErrors = false,
+            params byte[][] certificates)
+        {
+            _tlsOptions = new MqttClientTlsOptions
+            {
+                UseTls = true,
+                AllowUntrustedCertificates = allowUntrustedCertificates,
+                IgnoreCertificateChainErrors = ignoreCertificateChainErrors,
+                IgnoreCertificateRevocationErrors = ignoreCertificateRevocationErrors,
+                Certificates = certificates?.ToList()
+            };
+
+            return this;
+        }
+
+        public MqttClientOptionsBuilder WithTls()
+        {
+            _tlsOptions = new MqttClientTlsOptions
+            {
+                UseTls = true
+            };
+
+            return this;
+        }
+
+        public IMqttClientOptions Build()
+        {
+            if (_tlsOptions != null)
+            {
+                if (_tcpOptions == null && _webSocketOptions == null)
+                {
+                    throw new InvalidOperationException("A channel (TCP or WebSocket) must be set if TLS is configured.");
+                }
+
+                if (_tcpOptions != null)
+                {
+                    _tcpOptions.TlsOptions = _tlsOptions;
+                }
+                else if (_webSocketOptions != null)
+                {
+                    _webSocketOptions.TlsOptions = _tlsOptions;
+                }
+            }
+
+            _options.ChannelOptions = (IMqttClientChannelOptions)_tcpOptions ?? _webSocketOptions;
+
+            return _options;
+        }
+    }
+}
@@ -0,0 +1,13 @@
+namespace MQTTnet.Client
+{
+    public class MqttClientTcpOptions : IMqttClientChannelOptions
+    {
+        public string Server { get; set; }
+
+        public int? Port { get; set; }
+
+        public int BufferSize { get; set; } = 20 * 4096;
+
+        public MqttClientTlsOptions TlsOptions { get; set; } = new MqttClientTlsOptions();
+    }
+}
@@ -1,6 +1,6 @@
 using System;

-namespace MQTTnet.Core.Client
+namespace MQTTnet.Client
 {
    public static class MqttClientTcpOptionsExtensions
    {
@@ -1,8 +1,8 @@
 using System.Collections.Generic;

-namespace MQTTnet.Core.Client
+namespace MQTTnet.Client
 {
-    public sealed class MqttClientTlsOptions
+    public class MqttClientTlsOptions
    {
        public bool UseTls { get; set; }

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Net;
+
+namespace MQTTnet.Client
+{
+    public class MqttClientWebSocketOptions : IMqttClientChannelOptions
+    {
+        public string Uri { get; set; }
+
+        public IDictionary<string, string> RequestHeaders { get; set; }
+
+        public ICollection<string> SubProtocols { get; set; } = new List<string> { "mqtt" };
+
+        public CookieContainer CookieContainer { get; set; }
+
+        public MqttClientTlsOptions TlsOptions { get; set; } = new MqttClientTlsOptions();
+    }
+}
@@ -0,0 +1,97 @@
+using System;
+using System.Collections.Concurrent;
+using System.Threading.Tasks;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+
+namespace MQTTnet.Client
+{
+    public class MqttPacketDispatcher
+    {
+        private readonly ConcurrentDictionary<Type, ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>> _awaiters = new ConcurrentDictionary<Type, ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>>();
+        private readonly IMqttNetLogger _logger;
+
+        public MqttPacketDispatcher(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public async Task<MqttBasePacket> WaitForPacketAsync(Type responseType, ushort? identifier, TimeSpan timeout)
+        {
+            var packetAwaiter = AddPacketAwaiter(responseType, identifier);
+            try
+            {
+                return await packetAwaiter.Task.TimeoutAfter(timeout).ConfigureAwait(false);
+            }
+            catch (MqttCommunicationTimedOutException)
+            {
+                _logger.Warning<MqttPacketDispatcher>("Timeout while waiting for packet of type '{0}'.", responseType.Name);
+                throw;
+            }
+            finally
+            {
+                RemovePacketAwaiter(responseType, identifier);
+            }
+        }
+
+        public void Dispatch(MqttBasePacket packet)
+        {
+            if (packet == null) throw new ArgumentNullException(nameof(packet));
+
+            var type = packet.GetType();
+
+            if (_awaiters.TryGetValue(type, out var byId))
+            {
+                ushort? identifier = 0;
+                if (packet is IMqttPacketWithIdentifier packetWithIdentifier)
+                {
+                    identifier = packetWithIdentifier.PacketIdentifier;
+                }
+
+                if (byId.TryRemove(identifier.Value, out var tcs))
+                {
+                    tcs.TrySetResult(packet);
+                    return;
+                }
+            }
+
+            throw new InvalidOperationException($"Packet of type '{type.Name}' not handled or dispatched.");
+        }
+
+        public void Reset()
+        {
+            _awaiters.Clear();
+        }
+
+        private TaskCompletionSource<MqttBasePacket> AddPacketAwaiter(Type responseType, ushort? identifier)
+        {
+            var tcs = new TaskCompletionSource<MqttBasePacket>();
+
+            if (!identifier.HasValue)
+            {
+                identifier = 0;
+            }
+
+            var byId = _awaiters.GetOrAdd(responseType, key => new ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>());
+            if (!byId.TryAdd(identifier.Value, tcs))
+            {
+                throw new InvalidOperationException($"The packet dispatcher already has an awaiter for packet of type '{responseType}' with identifier {identifier}.");
+            }
+
+            return tcs;
+        }
+
+        private void RemovePacketAwaiter(Type responseType, ushort? identifier)
+        {
+            if (!identifier.HasValue)
+            {
+                identifier = 0;
+            }
+
+            var byId = _awaiters.GetOrAdd(responseType, key => new ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>());
+            byId.TryRemove(identifier.Value, out var _);
+        }
+    }
+}
@@ -0,0 +1,32 @@
+namespace MQTTnet.Client
+{
+    public class MqttPacketIdentifierProvider
+    {
+        private readonly object _syncRoot = new object();
+        private ushort _value;
+
+        public void Reset()
+        {
+            lock (_syncRoot)
+            {
+                _value = 0;
+            }
+        }
+
+        public ushort GetNewPacketIdentifier()
+        {
+            lock (_syncRoot)
+            {
+                _value++;
+
+                if (_value == 0)
+                {
+                    // As per official MQTT documentation the package identifier should never be 0.
+                    _value = 1;
+                }
+
+                return _value;
+            }
+        }
+    }
+}
@@ -1,7 +1,6 @@
-using MQTTnet.Core.Packets;
-using MQTTnet.Core.Protocol;
+using MQTTnet.Protocol;

-namespace MQTTnet.Core.Client
+namespace MQTTnet.Client
 {
    public class MqttSubscribeResult
    {
@@ -0,0 +1,21 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public interface IMqttNetLogger
+    {
+        event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
+
+        void Verbose<TSource>(string message, params object[] parameters);
+
+        void Info<TSource>(string message, params object[] parameters);
+
+        void Warning<TSource>(Exception exception, string message, params object[] parameters);
+
+        void Warning<TSource>(string message, params object[] parameters);
+
+        void Error<TSource>(Exception exception, string message, params object[] parameters);
+
+        void Error<TSource>(string message, params object[] parameters);
+    }
+}
@@ -0,0 +1,18 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public static class MqttNetGlobalLogger
+    {
+        public static event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
+
+        public static bool HasListeners => LogMessagePublished != null;
+
+        public static void Publish(MqttNetLogMessage logMessage)
+        {
+            if (logMessage == null) throw new ArgumentNullException(nameof(logMessage));
+
+            LogMessagePublished?.Invoke(null, new MqttNetLogMessagePublishedEventArgs(logMessage));
+        }
+    }
+}
@@ -0,0 +1,13 @@
+namespace MQTTnet.Diagnostics
+{
+    public enum MqttNetLogLevel
+    {
+        Verbose,
+
+        Info,
+
+        Warning,
+
+        Error
+    }
+}
@@ -0,0 +1,43 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public sealed class MqttNetLogMessage
+    {
+        public MqttNetLogMessage(string logId, DateTime timestamp, int threadId, string source, MqttNetLogLevel level, string message, Exception exception)
+        {
+            LogId = logId;
+            Timestamp = timestamp;
+            ThreadId = threadId;
+            Source = source;
+            Level = level;
+            Message = message;
+            Exception = exception;
+        }
+
+        public string LogId { get; }
+
+        public DateTime Timestamp { get; }
+
+        public int ThreadId { get; }
+
+        public string Source { get; }
+
+        public MqttNetLogLevel Level { get; }
+
+        public string Message { get; }
+
+        public Exception Exception { get; }
+
+        public override string ToString()
+        {
+            var result = $"[{Timestamp:O}] [{LogId}] [{ThreadId}] [{Source}] [{Level}]: {Message}";
+            if (Exception != null)
+            {
+                result += Environment.NewLine + Exception;
+            }
+
+            return result;
+        }
+    }
+}
@@ -0,0 +1,14 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public sealed class MqttNetLogMessagePublishedEventArgs : EventArgs
+    {
+        public MqttNetLogMessagePublishedEventArgs(MqttNetLogMessage logMessage)
+        {
+            TraceMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+        }
+
+        public MqttNetLogMessage TraceMessage { get; }
+    }
+}
@@ -0,0 +1,74 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public class MqttNetLogger : IMqttNetLogger
+    {
+        private readonly string _logId;
+
+        public MqttNetLogger(string logId = null)
+        {
+            _logId = logId;
+        }
+
+        public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
+
+        public void Verbose<TSource>(string message, params object[] parameters)
+        {
+            Publish<TSource>(MqttNetLogLevel.Verbose, null, message, parameters);
+        }
+
+        public void Info<TSource>(string message, params object[] parameters)
+        {
+            Publish<TSource>(MqttNetLogLevel.Info, null, message, parameters);
+        }
+
+        public void Warning<TSource>(Exception exception, string message, params object[] parameters)
+        {
+            Publish<TSource>(MqttNetLogLevel.Warning, exception, message, parameters);
+        }
+
+        public void Warning<TSource>(string message, params object[] parameters)
+        {
+            Warning<TSource>(null, message, parameters);
+        }
+
+        public void Error<TSource>(Exception exception, string message, params object[] parameters)
+        {
+            Publish<TSource>(MqttNetLogLevel.Error, exception, message, parameters);
+        }
+
+        public void Error<TSource>(string message, params object[] parameters)
+        {
+            Warning<TSource>(null, message, parameters);
+        }
+
+        private void Publish<TSource>(MqttNetLogLevel logLevel, Exception exception, string message, object[] parameters)
+        {
+            var hasLocalListeners = LogMessagePublished != null;
+            var hasGlobalListeners = MqttNetGlobalLogger.HasListeners;
+
+            if (!hasLocalListeners && !hasGlobalListeners)
+            {
+                return;
+            }
+
+            if (parameters.Length > 0)
+            {
+                message = string.Format(message, parameters);
+            }
+
+            var traceMessage = new MqttNetLogMessage(_logId, DateTime.Now, Environment.CurrentManagedThreadId, typeof(TSource).Name, logLevel, message, exception);
+
+            if (hasGlobalListeners)
+            {
+                MqttNetGlobalLogger.Publish(traceMessage);
+            }
+
+            if (hasLocalListeners)
+            {
+                LogMessagePublished?.Invoke(this, new MqttNetLogMessagePublishedEventArgs(traceMessage));
+            }
+        }
+    }
+}
@@ -0,0 +1,23 @@
+namespace MQTTnet.Diagnostics
+{
+    public static class TargetFrameworkInfoProvider
+    {
+        public static string TargetFramework
+        {
+            get
+            {
+#if NET452
+                return "net452";
+#elif NET461
+                return "net461";
+#elif NETSTANDARD1_3
+                return "netstandard1.3";
+#elif NETSTANDARD2_0
+                return "netstandard2.0";
+#elif WINDOWS_UWP
+                return "uap10.0";
+#endif
+            }
+        }
+    }
+}
@@ -1,6 +1,6 @@
 using System;

-namespace MQTTnet.Core.Exceptions
+namespace MQTTnet.Exceptions
 {
    public class MqttCommunicationException : Exception
    {
@@ -17,10 +17,5 @@ namespace MQTTnet.Core.Exceptions
            : base(message)
        {
        }
-
-        public MqttCommunicationException(string message, Exception innerException)
-            : base(message, innerException)
-        {
-        }
    }
 }
@@ -1,4 +1,4 @@
-namespace MQTTnet.Core.Exceptions
+namespace MQTTnet.Exceptions
 {
    public sealed class MqttCommunicationTimedOutException : MqttCommunicationException
    {
@@ -1,6 +1,6 @@
 using System;

-namespace MQTTnet.Core.Exceptions
+namespace MQTTnet.Exceptions
 {
    public sealed class MqttProtocolViolationException : Exception
    {
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace MQTTnet
+{
+    public interface IApplicationMessagePublisher
+    {
+        Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages);
+    }
+}
@@ -0,0 +1,9 @@
+using System;
+
+namespace MQTTnet
+{
+    public interface IApplicationMessageReceiver
+    {
+        event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
+    }
+}
@@ -0,0 +1,36 @@
+using System;
+using MQTTnet.Adapter;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.Implementations
+{
+    public class MqttClientAdapterFactory : IMqttClientAdapterFactory
+    {
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            var serializer = new MqttPacketSerializer { ProtocolVersion = options.ProtocolVersion };
+
+            switch (options.ChannelOptions)
+            {
+                case MqttClientTcpOptions tcpOptions:
+                    {
+                        return new MqttChannelAdapter(new MqttTcpChannel(tcpOptions), serializer, logger);
+                    }
+
+                case MqttClientWebSocketOptions webSocketOptions:
+                    {
+                        return new MqttChannelAdapter(new MqttWebSocketChannel(webSocketOptions), serializer, logger);
+                    }
+
+                default:
+                    {
+                        throw new NotSupportedException();
+                    }
+            }
+        }
+    }
+}
@@ -1,27 +0,0 @@
-using System;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet.Implementations
-{
-    public class MqttCommunicationAdapterFactory : IMqttCommunicationAdapterFactory
-    {
-        public IMqttCommunicationAdapter CreateMqttCommunicationAdapter(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            if (options is MqttClientTcpOptions tcpOptions)
-            {
-                return new MqttChannelCommunicationAdapter(new MqttTcpChannel(tcpOptions), new MqttPacketSerializer { ProtocolVersion = options.ProtocolVersion });
-            }
-
-            if (options is MqttClientWebSocketOptions webSocketOptions)
-            {
-                return new MqttChannelCommunicationAdapter(new MqttWebSocketChannel(webSocketOptions), new MqttPacketSerializer { ProtocolVersion = options.ProtocolVersion });
-            }
-
-            throw new NotSupportedException();
-        }
-    }
-}
@@ -1,129 +0,0 @@
-using System;
-using System.Net;
-using System.Net.Security;
-using System.Net.Sockets;
-using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Diagnostics;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet.Implementations
-{
-    public class MqttServerAdapter : IMqttServerAdapter, IDisposable
-    {
-        private CancellationTokenSource _cancellationTokenSource;
-        private Socket _defaultEndpointSocket;
-        private Socket _tlsEndpointSocket;
-        private X509Certificate2 _tlsCertificate;
-
-        private bool _isRunning;
-
-        public event Action<IMqttCommunicationAdapter> ClientAccepted;
-
-        public Task StartAsync(MqttServerOptions options)
-        {
-            if (_isRunning) throw new InvalidOperationException("Server is already started.");
-
-            _isRunning = true;
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            if (options.DefaultEndpointOptions.IsEnabled)
-            {
-                _defaultEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-                _defaultEndpointSocket.Bind(new IPEndPoint(IPAddress.Any, options.GetDefaultEndpointPort()));
-                _defaultEndpointSocket.Listen(options.ConnectionBacklog);
-
-                Task.Run(() => AcceptDefaultEndpointConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-            }
-
-            if (options.TlsEndpointOptions.IsEnabled)
-            {
-                if (options.TlsEndpointOptions.Certificate == null)
-                {
-                    throw new ArgumentException("TLS certificate is not set.");
-                }
-
-                _tlsCertificate = new X509Certificate2(options.TlsEndpointOptions.Certificate);
-
-                _tlsEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-                _tlsEndpointSocket.Bind(new IPEndPoint(IPAddress.Any, options.GetTlsEndpointPort()));
-                _tlsEndpointSocket.Listen(options.ConnectionBacklog);
-
-                Task.Run(() => AcceptTlsEndpointConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-            }
-
-            return Task.FromResult(0);
-        }
-
-        public Task StopAsync()
-        {
-            _isRunning = false;
-
-            _cancellationTokenSource?.Cancel(false);
-            _cancellationTokenSource?.Dispose();
-            _cancellationTokenSource = null;
-
-            _defaultEndpointSocket?.Dispose();
-            _defaultEndpointSocket = null;
-
-            _tlsEndpointSocket?.Dispose();
-            _tlsEndpointSocket = null;
-
-            return Task.FromResult(0);
-        }
-
-        public void Dispose()
-        {
-            StopAsync();
-        }
-
-        private async Task AcceptDefaultEndpointConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                try
-                {
-                    var clientSocket = await _defaultEndpointSocket.AcceptAsync().ConfigureAwait(false);
-                    var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, null), new MqttPacketSerializer());
-                    ClientAccepted?.Invoke(clientAdapter);
-                }
-                catch (Exception exception)
-                {
-                    MqttNetTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at default endpoint.");
-
-                    //excessive CPU consumed if in endless loop of socket errors
-                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
-                }
-            }
-        }
-
-        private async Task AcceptTlsEndpointConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                try
-                {
-                    var clientSocket = await _tlsEndpointSocket.AcceptAsync().ConfigureAwait(false);
-
-                    var sslStream = new SslStream(new NetworkStream(clientSocket));
-                    await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
-
-                    var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, sslStream), new MqttPacketSerializer());
-                    ClientAccepted?.Invoke(clientAdapter);
-                }
-                catch (Exception exception)
-                {
-                    MqttNetTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at TLS endpoint.");
-
-                    //excessive CPU consumed if in endless loop of socket errors
-                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
-                }
-            }
-        }
-    }
-}
@@ -1,3 +1,4 @@
+#if WINDOWS_UWP
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -7,19 +8,26 @@ using System.Threading.Tasks;
 using Windows.Networking;
 using Windows.Networking.Sockets;
 using Windows.Security.Cryptography.Certificates;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
+using MQTTnet.Channel;
+using MQTTnet.Client;

 namespace MQTTnet.Implementations
 {
-    public sealed class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
+    public sealed class MqttTcpChannel : IMqttChannel
    {
+        // ReSharper disable once MemberCanBePrivate.Global
+        // ReSharper disable once AutoPropertyCanBeMadeGetOnly.Global
+        public static int BufferSize { get; set; } = 4096 * 20; // Can be changed for fine tuning by library user.
+
+        private readonly int _bufferSize = BufferSize;
        private readonly MqttClientTcpOptions _options;
+
        private StreamSocket _socket;

        public MqttTcpChannel(MqttClientTcpOptions options)
        {
            _options = options ?? throw new ArgumentNullException(nameof(options));
+            _bufferSize = _options.BufferSize;
        }

        public MqttTcpChannel(StreamSocket socket)
@@ -31,7 +39,6 @@ namespace MQTTnet.Implementations

        public Stream SendStream { get; private set; }
        public Stream ReceiveStream { get; private set; }
-        public Stream RawReceiveStream { get; private set; }

        public static Func<MqttClientTcpOptions, IEnumerable<ChainValidationResult>> CustomIgnorableServerCertificateErrorsResolver { get; set; }

@@ -69,27 +76,59 @@ namespace MQTTnet.Implementations

        public void Dispose()
        {
-            RawReceiveStream?.Dispose();
-            RawReceiveStream = null;
+            try
+            {
+                SendStream?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                SendStream = null;
+            }

-            SendStream?.Dispose();
-            SendStream = null;
+            try
+            {
+                ReceiveStream?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                ReceiveStream = null;
+            }

-            ReceiveStream?.Dispose();
-            ReceiveStream = null;
-
-            _socket?.Dispose();
-            _socket = null;
+            try
+            {
+                _socket?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                _socket = null;
+            }
        }

        private void CreateStreams()
        {
-            SendStream = _socket.OutputStream.AsStreamForWrite();
-            ReceiveStream = _socket.InputStream.AsStreamForRead();
-            RawReceiveStream = ReceiveStream;
+            SendStream = _socket.OutputStream.AsStreamForWrite(_bufferSize);
+            ReceiveStream = _socket.InputStream.AsStreamForRead(_bufferSize);
        }

-        private static Certificate LoadCertificate(MqttClientOptions options)
+        private static Certificate LoadCertificate(MqttClientTcpOptions options)
        {
            if (options.TlsOptions.Certificates == null || !options.TlsOptions.Certificates.Any())
            {
@@ -133,4 +172,5 @@ namespace MQTTnet.Implementations
            return result;
        }
    }
-}
+}
+#endif
@@ -1,29 +1,41 @@
+#if NET452 || NET461 || NETSTANDARD1_3 || NETSTANDARD2_0
 using System;
 using System.Net.Security;
 using System.Net.Sockets;
 using System.Security.Authentication;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading.Tasks;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
 using System.IO;
 using System.Linq;
+using MQTTnet.Channel;
+using MQTTnet.Client;

 namespace MQTTnet.Implementations
 {
-    public sealed class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
+    public sealed class MqttTcpChannel : IMqttChannel
    {
+#if NET452 || NET461
+        // ReSharper disable once MemberCanBePrivate.Global
+        // ReSharper disable once AutoPropertyCanBeMadeGetOnly.Global
+        public static int BufferSize { get; set; } = 4096 * 20; // Can be changed for fine tuning by library user.
+
+        private readonly int _bufferSize = BufferSize;
+#else
+        private readonly int _bufferSize = 0;
+#endif
+
        private readonly MqttClientTcpOptions _options;

        private Socket _socket;
        private SslStream _sslStream;
-        
+
        /// <summary>
        /// called on client sockets are created in connect
        /// </summary>
        public MqttTcpChannel(MqttClientTcpOptions options)
        {
            _options = options ?? throw new ArgumentNullException(nameof(options));
+            _bufferSize = options.BufferSize;
        }

        /// <summary>
@@ -34,12 +46,12 @@ namespace MQTTnet.Implementations
        {
            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
            _sslStream = sslStream;
-            ReceiveStream = (Stream)sslStream ?? new NetworkStream(socket);
+
+            CreateStreams();
        }

-        public Stream SendStream => ReceiveStream;
+        public Stream SendStream { get; private set; }
        public Stream ReceiveStream { get; private set; }
-        public Stream RawReceiveStream => ReceiveStream;

        public static Func<X509Certificate, X509Chain, SslPolicyErrors, MqttClientTcpOptions, bool> CustomCertificateValidationCallback { get; set; }

@@ -50,18 +62,19 @@ namespace MQTTnet.Implementations
                _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
            }

+#if NET452 || NET461
+            await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, _options.Server, _options.GetPort(), null).ConfigureAwait(false);
+#else
            await _socket.ConnectAsync(_options.Server, _options.GetPort()).ConfigureAwait(false);
+#endif

            if (_options.TlsOptions.UseTls)
            {
                _sslStream = new SslStream(new NetworkStream(_socket, true), false, InternalUserCertificateValidationCallback);
-                ReceiveStream = _sslStream;
-                await _sslStream.AuthenticateAsClientAsync(_options.Server, LoadCertificates(_options), SslProtocols.Tls12, _options.TlsOptions.IgnoreCertificateRevocationErrors).ConfigureAwait(false);
-            }
-            else
-            {
-                ReceiveStream = new NetworkStream(_socket);
+                await _sslStream.AuthenticateAsClientAsync(_options.Server, LoadCertificates(), SslProtocols.Tls12, _options.TlsOptions.IgnoreCertificateRevocationErrors).ConfigureAwait(false);
            }
+            
+            CreateStreams();
        }

        public Task DisconnectAsync()
@@ -72,11 +85,70 @@ namespace MQTTnet.Implementations

        public void Dispose()
        {
-            _socket?.Dispose();
-            _socket = null;
+            var oneStreamIsUsed = SendStream != null && ReceiveStream != null && ReferenceEquals(SendStream, ReceiveStream);

-            _sslStream?.Dispose();
-            _sslStream = null;
+            try
+            {
+                SendStream?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                SendStream = null;
+            }
+
+            try
+            {
+                if (!oneStreamIsUsed)
+                {
+                    ReceiveStream?.Dispose();
+                }
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                ReceiveStream = null;
+            }
+
+            try
+            {
+                _sslStream?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                _sslStream = null;
+            }
+
+            try
+            {
+                _socket?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            catch (NullReferenceException)
+            {
+            }
+            finally
+            {
+                _socket = null;
+            }
        }

        private bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
@@ -110,20 +182,42 @@ namespace MQTTnet.Implementations
            return _options.TlsOptions.AllowUntrustedCertificates;
        }

-        private static X509CertificateCollection LoadCertificates(MqttClientOptions options)
+        private X509CertificateCollection LoadCertificates()
        {
            var certificates = new X509CertificateCollection();
-            if (options.TlsOptions.Certificates == null)
+            if (_options.TlsOptions.Certificates == null)
            {
                return certificates;
            }

-            foreach (var certificate in options.TlsOptions.Certificates)
+            foreach (var certificate in _options.TlsOptions.Certificates)
            {
-                certificates.Add(new X509Certificate(certificate));
+                certificates.Add(new X509Certificate2(certificate));
            }

            return certificates;
        }
+
+        private void CreateStreams()
+        {
+            Stream stream;
+            if (_sslStream != null)
+            {
+                stream = _sslStream;
+            }
+            else
+            {
+                stream = new NetworkStream(_socket, true);
+            }
+            
+#if NET452 || NET461
+            SendStream = new BufferedStream(stream, _bufferSize);
+            ReceiveStream = new BufferedStream(stream, _bufferSize);
+#else
+            SendStream = stream;
+            ReceiveStream = stream;
+#endif
+        }
    }
-}
+}
+#endif
@@ -1,29 +1,32 @@
+#if WINDOWS_UWP
 using System;
 using System.Threading.Tasks;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Diagnostics;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
 using Windows.Networking.Sockets;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Serializer;
+using MQTTnet.Server;

 namespace MQTTnet.Implementations
 {
-    public class MqttServerAdapter : IMqttServerAdapter, IDisposable
+    public class MqttTcpServerAdapter : IMqttServerAdapter, IDisposable
    {
+        private readonly IMqttNetLogger _logger;
        private StreamSocketListener _defaultEndpointSocket;

-        private bool _isRunning;
+        public MqttTcpServerAdapter(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }

-        public event Action<IMqttCommunicationAdapter> ClientAccepted;
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;

-        public async Task StartAsync(MqttServerOptions options)
+        public async Task StartAsync(IMqttServerOptions options)
        {
            if (options == null) throw new ArgumentNullException(nameof(options));

-            if (_isRunning) throw new InvalidOperationException("Server is already started.");
-
-            _isRunning = true;
-
+            if (_defaultEndpointSocket != null) throw new InvalidOperationException("Server is already started.");
+            
            if (options.DefaultEndpointOptions.IsEnabled)
            {
                _defaultEndpointSocket = new StreamSocketListener();
@@ -39,7 +42,10 @@ namespace MQTTnet.Implementations

        public Task StopAsync()
        {
-            _isRunning = false;
+            if (_defaultEndpointSocket != null)
+            {
+                _defaultEndpointSocket.ConnectionReceived -= AcceptDefaultEndpointConnectionsAsync;
+            }

            _defaultEndpointSocket?.Dispose();
            _defaultEndpointSocket = null;
@@ -56,13 +62,14 @@ namespace MQTTnet.Implementations
        {
            try
            {
-                var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(args.Socket), new MqttPacketSerializer());
-                ClientAccepted?.Invoke(clientAdapter);
+                var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(args.Socket), new MqttPacketSerializer(), _logger);
+                ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
            }
            catch (Exception exception)
            {
-                MqttNetTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at default endpoint.");
+                _logger.Error<MqttTcpServerAdapter>(exception, "Error while accepting connection at default endpoint.");
            }
        }
    }
-}
+}
+#endif
@@ -0,0 +1,162 @@
+#if NET452 || NET461 || NETSTANDARD1_3 || NETSTANDARD2_0
+using System;
+using System.Net;
+using System.Net.Security;
+using System.Net.Sockets;
+using System.Security.Authentication;
+using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Serializer;
+using MQTTnet.Server;
+
+namespace MQTTnet.Implementations
+{
+    public class MqttTcpServerAdapter : IMqttServerAdapter, IDisposable
+    {
+        private readonly IMqttNetLogger _logger;
+
+        private CancellationTokenSource _cancellationTokenSource;
+        private Socket _defaultEndpointSocket;
+        private Socket _tlsEndpointSocket;
+        private X509Certificate2 _tlsCertificate;
+
+        public MqttTcpServerAdapter(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public Task StartAsync(IMqttServerOptions options)
+        {
+            if (_cancellationTokenSource != null) throw new InvalidOperationException("Server is already started.");
+
+            _cancellationTokenSource = new CancellationTokenSource();
+
+            if (options.DefaultEndpointOptions.IsEnabled)
+            {
+                _defaultEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+                _defaultEndpointSocket.Bind(new IPEndPoint(options.DefaultEndpointOptions.BoundIPAddress, options.GetDefaultEndpointPort()));
+                _defaultEndpointSocket.Listen(options.ConnectionBacklog);
+
+                Task.Run(async () => await AcceptDefaultEndpointConnectionsAsync(_cancellationTokenSource.Token).ConfigureAwait(false), _cancellationTokenSource.Token).ConfigureAwait(false);
+            }
+
+            if (options.TlsEndpointOptions.IsEnabled)
+            {
+                if (options.TlsEndpointOptions.Certificate == null)
+                {
+                    throw new ArgumentException("TLS certificate is not set.");
+                }
+
+                _tlsCertificate = new X509Certificate2(options.TlsEndpointOptions.Certificate);
+                if (!_tlsCertificate.HasPrivateKey)
+                {
+                    throw new InvalidOperationException("The certificate for TLS encryption must contain the private key.");
+                }
+
+                _tlsEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+                _tlsEndpointSocket.Bind(new IPEndPoint(options.TlsEndpointOptions.BoundIPAddress, options.GetTlsEndpointPort()));
+                _tlsEndpointSocket.Listen(options.ConnectionBacklog);
+
+                Task.Run(async () => await AcceptTlsEndpointConnectionsAsync(_cancellationTokenSource.Token).ConfigureAwait(false), _cancellationTokenSource.Token).ConfigureAwait(false);
+            }
+
+            return Task.FromResult(0);
+        }
+
+        public Task StopAsync()
+        {
+            _cancellationTokenSource?.Cancel(false);
+            _cancellationTokenSource?.Dispose();
+            _cancellationTokenSource = null;
+
+            _defaultEndpointSocket?.Dispose();
+            _defaultEndpointSocket = null;
+
+            _tlsCertificate = null;
+            
+            _tlsEndpointSocket?.Dispose();
+            _tlsEndpointSocket = null;
+
+            return Task.FromResult(0);
+        }
+
+        public void Dispose()
+        {
+            StopAsync();
+        }
+
+        private async Task AcceptDefaultEndpointConnectionsAsync(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    //todo: else branch can be used with min dependency NET46
+#if NET452 || NET461
+                    var clientSocket = await Task.Factory.FromAsync(_defaultEndpointSocket.BeginAccept, _defaultEndpointSocket.EndAccept, null).ConfigureAwait(false);
+#else
+                    var clientSocket = await _defaultEndpointSocket.AcceptAsync().ConfigureAwait(false);
+#endif
+
+                    var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(clientSocket, null), new MqttPacketSerializer(), _logger);
+                    ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
+                }
+                catch (ObjectDisposedException)
+                {
+                    // It can happen that the listener socket is accessed after the cancellation token is already set and the listener socket is disposed.
+                }
+                catch (Exception exception)
+                {
+                    if (exception is SocketException s && s.SocketErrorCode == SocketError.OperationAborted)
+                    {
+                        return;
+                    }
+
+                    _logger.Error<MqttTcpServerAdapter>(exception, "Error while accepting connection at default endpoint.");
+                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
+                }
+            }
+        }
+
+        private async Task AcceptTlsEndpointConnectionsAsync(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+#if NET452 || NET461
+                    var clientSocket = await Task.Factory.FromAsync(_tlsEndpointSocket.BeginAccept, _tlsEndpointSocket.EndAccept, null).ConfigureAwait(false);
+#else
+                    var clientSocket = await _tlsEndpointSocket.AcceptAsync().ConfigureAwait(false);
+#endif
+
+                    var sslStream = new SslStream(new NetworkStream(clientSocket));
+                    await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
+                    
+                    var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(clientSocket, sslStream), new MqttPacketSerializer(), _logger);
+                    ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
+                }
+                catch (ObjectDisposedException)
+                {
+                    // It can happen that the listener socket is accessed after the cancellation token is already set and the listener socket is disposed.
+                }
+                catch (Exception exception)
+                {
+                    if (exception is SocketException s && s.SocketErrorCode == SocketError.OperationAborted)
+                    {
+                        return;
+                    }
+
+                    _logger.Error<MqttTcpServerAdapter>(exception, "Error while accepting connection at TLS endpoint.");
+                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
+                }
+            }
+        }
+    }
+}
+#endif
@@ -1,15 +1,20 @@
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using System;
+using System;
 using System.IO;
 using System.Net.WebSockets;
+using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Channel;
+using MQTTnet.Client;

 namespace MQTTnet.Implementations
 {
-    public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
+    public sealed class MqttWebSocketChannel : IMqttChannel
    {
+        // ReSharper disable once MemberCanBePrivate.Global
+        // ReSharper disable once AutoPropertyCanBeMadeGetOnly.Global
+        public static int BufferSize { get; set; } = 4096 * 20; // Can be changed for fine tuning by library user.
+
        private readonly MqttClientWebSocketOptions _options;
        private ClientWebSocket _webSocket;

@@ -18,39 +23,90 @@ namespace MQTTnet.Implementations
            _options = options ?? throw new ArgumentNullException(nameof(options));
        }

-        public Stream SendStream => RawReceiveStream;
-        public Stream ReceiveStream => RawReceiveStream;
-        public Stream RawReceiveStream { get; private set; }
+        public Stream SendStream { get; private set; }
+        public Stream ReceiveStream { get; private set; }

        public async Task ConnectAsync()
        {
            var uri = _options.Uri;
-            if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase))
+            if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase) && !uri.StartsWith("wss://", StringComparison.OrdinalIgnoreCase))
            {
-                uri = "ws://" + uri;
+                if (_options.TlsOptions?.UseTls == false)
+                {
+                    uri = "ws://" + uri;
+                }
+                else
+                {
+                    uri = "wss://" + uri;
+                }
            }

            _webSocket = new ClientWebSocket();
-            _webSocket.Options.KeepAliveInterval = _options.KeepAlivePeriod;
-            await _webSocket.ConnectAsync(new Uri(uri), CancellationToken.None);
-            RawReceiveStream = new WebSocketStream(_webSocket);
+            
+            if (_options.RequestHeaders != null)
+            {
+                foreach (var requestHeader in _options.RequestHeaders)
+                {
+                    _webSocket.Options.SetRequestHeader(requestHeader.Key, requestHeader.Value);
+                }    
+            }
+
+            if (_options.SubProtocols != null)
+            {
+                foreach (var subProtocol in _options.SubProtocols)
+                {
+                    _webSocket.Options.AddSubProtocol(subProtocol);
+                }
+            }
+
+            if (_options.CookieContainer != null)
+            {
+                _webSocket.Options.Cookies = _options.CookieContainer;
+            }
+
+            if (_options.TlsOptions?.UseTls == true && _options.TlsOptions?.Certificates != null)
+            {
+                _webSocket.Options.ClientCertificates = new X509CertificateCollection();
+                foreach (var certificate in _options.TlsOptions.Certificates)
+                {
+                    _webSocket.Options.ClientCertificates.Add(new X509Certificate(certificate));
+                }
+            }
+
+            await _webSocket.ConnectAsync(new Uri(uri), CancellationToken.None).ConfigureAwait(false);
+
+            SendStream = new WebSocketStream(_webSocket);
+            ReceiveStream = SendStream;
        }

        public async Task DisconnectAsync()
        {
-            RawReceiveStream = null;
-
            if (_webSocket == null)
            {
                return;
            }

-            await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
+            if (_webSocket.State == WebSocketState.Open || _webSocket.State == WebSocketState.Connecting)
+            {
+                await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
+            }
+
+            Dispose();
        }

        public void Dispose()
        {
-            _webSocket?.Dispose();
+            try
+            {
+                _webSocket?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            finally
+            {
+                _webSocket = null;
+            }            
        }
    }
 }
@@ -1,18 +1,23 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Net.WebSockets;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Exceptions;

 namespace MQTTnet.Implementations
 {
    public class WebSocketStream : Stream
    {
-        private readonly ClientWebSocket _webSocket;
-        
-        public WebSocketStream(ClientWebSocket webSocket)
+        private readonly byte[] _chunckBuffer = new byte[MqttWebSocketChannel.BufferSize];
+        private readonly Queue<byte> _buffer = new Queue<byte>(MqttWebSocketChannel.BufferSize);
+        private readonly WebSocket _webSocket;
+
+        public WebSocketStream(WebSocket webSocket)
        {
-            _webSocket = webSocket;
+            _webSocket = webSocket ?? throw new ArgumentNullException(nameof(webSocket));
        }

        public override bool CanRead => true;
@@ -33,27 +38,9 @@ namespace MQTTnet.Implementations
        {
        }

-        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        public override Task FlushAsync(CancellationToken cancellationToken)
        {
-            var currentOffset = offset;
-            var targetOffset = offset + count;
-            while (_webSocket.State == WebSocketState.Open && currentOffset < targetOffset)
-            {
-                var response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer, currentOffset, count), cancellationToken).ConfigureAwait(false);
-                currentOffset += response.Count;
-
-                if (response.MessageType == WebSocketMessageType.Close)
-                {
-                    await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, cancellationToken).ConfigureAwait(false);
-                }
-            }
-
-            return currentOffset - offset;
-        }
-
-        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        {
-            return _webSocket.SendAsync(new ArraySegment<byte>(buffer, offset, count), WebSocketMessageType.Binary, true, cancellationToken);
+            return Task.FromResult(0);
        }

        public override int Read(byte[] buffer, int offset, int count)
@@ -61,11 +48,61 @@ namespace MQTTnet.Implementations
            return ReadAsync(buffer, offset, count).GetAwaiter().GetResult();
        }

+        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            var bytesRead = 0;
+
+            // Use existing date from buffer.
+            while (count > 0 && _buffer.Any())
+            {
+                buffer[offset] = _buffer.Dequeue();
+                count--;
+                bytesRead++;
+                offset++;
+            }
+
+            if (count == 0)
+            {
+                return bytesRead;
+            }
+
+            // Fetch new data if the buffer is not full.
+            while (_webSocket.State == WebSocketState.Open)
+            {
+                await FetchChunkAsync(cancellationToken).ConfigureAwait(false);
+
+                while (count > 0 && _buffer.Any())
+                {
+                    buffer[offset] = _buffer.Dequeue();
+                    count--;
+                    bytesRead++;
+                    offset++;
+                }
+
+                if (count == 0)
+                {
+                    return bytesRead;
+                }
+            }
+
+            if (_webSocket.State == WebSocketState.Closed)
+            {
+                throw new MqttCommunicationException("WebSocket connection closed.");
+            }
+
+            return bytesRead;
+        }
+
        public override void Write(byte[] buffer, int offset, int count)
        {
            WriteAsync(buffer, offset, count).GetAwaiter().GetResult();
        }

+        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            return _webSocket.SendAsync(new ArraySegment<byte>(buffer, offset, count), WebSocketMessageType.Binary, true, cancellationToken);
+        }
+
        public override long Seek(long offset, SeekOrigin origin)
        {
            throw new NotSupportedException();
@@ -75,5 +112,26 @@ namespace MQTTnet.Implementations
        {
            throw new NotSupportedException();
        }
+
+        private async Task FetchChunkAsync(CancellationToken cancellationToken)
+        {   
+            var response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(_chunckBuffer, 0, _chunckBuffer.Length), cancellationToken).ConfigureAwait(false);
+
+            if (response.MessageType == WebSocketMessageType.Close)
+            {
+                await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, cancellationToken).ConfigureAwait(false);
+            }
+            else if (response.MessageType == WebSocketMessageType.Binary)
+            {
+                for (var i = 0; i < response.Count; i++)
+                {
+                    _buffer.Enqueue(_chunckBuffer[i]);
+                }
+            }
+            else if (response.MessageType == WebSocketMessageType.Text)
+            {
+                throw new MqttProtocolViolationException("WebSocket channel received TEXT message.");
+            }
+        }
    }
 }
@@ -1,17 +1,18 @@
-using MQTTnet.Core.Packets;
+using MQTTnet.Packets;

-namespace MQTTnet.Core.Internal
+namespace MQTTnet.Internal
 {
    internal static class MqttApplicationMessageExtensions
    {
        public static MqttApplicationMessage ToApplicationMessage(this MqttPublishPacket publishPacket)
        {
-            return new MqttApplicationMessage(
-                publishPacket.Topic,
-                publishPacket.Payload,
-                publishPacket.QualityOfServiceLevel,
-                publishPacket.Retain
-            );
+            return new MqttApplicationMessage
+            { 
+                Topic = publishPacket.Topic,
+                Payload = publishPacket.Payload,
+                QualityOfServiceLevel = publishPacket.QualityOfServiceLevel,
+                Retain = publishPacket.Retain
+            };
        }

        public static MqttPublishPacket ToPublishPacket(this MqttApplicationMessage applicationMessage)
@@ -1,21 +1,23 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Core.Exceptions;
+using MQTTnet.Exceptions;

-namespace MQTTnet.Core.Internal
+namespace MQTTnet.Internal
 {
    public static class TaskExtensions
    {
        public static async Task TimeoutAfter(this Task task, TimeSpan timeout)
        {
-            using (var cancellationTokenSource = new CancellationTokenSource())
+            if (task == null) throw new ArgumentNullException(nameof(task));
+
+            using (var timeoutCts = new CancellationTokenSource())
            {
                try
                {
-                    var timeoutTask = Task.Delay(timeout, cancellationTokenSource.Token);
+                    var timeoutTask = Task.Delay(timeout, timeoutCts.Token);
                    var finishedTask = await Task.WhenAny(timeoutTask, task).ConfigureAwait(false);
-
+                    
                    if (finishedTask == timeoutTask)
                    {
                        throw new MqttCommunicationTimedOutException();
@@ -28,23 +30,25 @@ namespace MQTTnet.Core.Internal

                    if (task.IsFaulted)
                    {
-                        throw new MqttCommunicationException(task.Exception.GetBaseException());
+                        throw new MqttCommunicationException(task.Exception?.GetBaseException());
                    }
                }
                finally
                {
-                    cancellationTokenSource.Cancel();
+                    timeoutCts.Cancel();
                }
            }
        }

        public static async Task<TResult> TimeoutAfter<TResult>(this Task<TResult> task, TimeSpan timeout)
        {
-            using (var cancellationTokenSource = new CancellationTokenSource())
+            if (task == null) throw new ArgumentNullException(nameof(task));
+
+            using (var timeoutCts = new CancellationTokenSource())
            {
                try
                {
-                    var timeoutTask = Task.Delay(timeout, cancellationTokenSource.Token);
+                    var timeoutTask = Task.Delay(timeout, timeoutCts.Token);
                    var finishedTask = await Task.WhenAny(timeoutTask, task).ConfigureAwait(false);

                    if (finishedTask == timeoutTask)
@@ -66,7 +70,7 @@ namespace MQTTnet.Core.Internal
                }
                finally
                {
-                    cancellationTokenSource.Cancel();
+                    timeoutCts.Cancel();
                }
            }
        }
@@ -1,32 +1,65 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFramework>netstandard1.3</TargetFramework>
+    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">netstandard1.3;netstandard2.0;net452;net461;uap10.0</TargetFrameworks>
+    <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netstandard1.3;netstandard2.0</TargetFrameworks>
    <AssemblyName>MQTTnet</AssemblyName>
    <RootNamespace>MQTTnet</RootNamespace>
-    <AssemblyVersion>2.4.0.0</AssemblyVersion>
-    <FileVersion>2.4.0.0</FileVersion>
+    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
+    <DebugType>Full</DebugType>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+    <FileVersion>0.0.0.0</FileVersion>
    <Version>0.0.0.0</Version>
    <Company />
    <Product />
    <Description />
    <Authors />
    <PackageId />
+    <SignAssembly>false</SignAssembly>
+    <DelaySign>false</DelaySign>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
+    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
+    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
+    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
+    <TargetPlatformVersion>10.0.16299.0</TargetPlatformVersion>
+    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
+    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
+    <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
+    <DefaultLanguage>en</DefaultLanguage>
+    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x86'" />

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" />

-  <ItemGroup>
-    <ProjectReference Include="..\..\MQTTnet.Core\MQTTnet.Core.csproj" />
-  </ItemGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Release|netstandard1.3|AnyCPU'">
+    <DefineConstants>RELEASE;NETSTANDARD1_3</DefineConstants>
+  </PropertyGroup>

-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)'=='netstandard2.0'">
    <PackageReference Include="System.Net.Security" Version="4.3.2" />
    <PackageReference Include="System.Net.WebSockets" Version="4.3.0" />
    <PackageReference Include="System.Net.WebSockets.Client" Version="4.3.1" />
-    <PackageReference Include="System.Threading.Thread" Version="4.3.0" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)'=='netstandard1.3'">
+    <PackageReference Include="System.Net.Security" Version="4.3.2" />
+    <PackageReference Include="System.Net.WebSockets" Version="4.3.0" />
+    <PackageReference Include="System.Net.WebSockets.Client" Version="4.3.1" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)'=='uap10.0'">
+    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="5.4.1" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)'=='net452'">
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)'=='net461'">
  </ItemGroup>

 </Project>
@@ -0,0 +1,19 @@
+using System;
+
+namespace MQTTnet.ManagedClient
+{
+    public class ApplicationMessageProcessedEventArgs : EventArgs
+    {
+        public ApplicationMessageProcessedEventArgs(MqttApplicationMessage applicationMessage, Exception exception)
+        {
+            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
+            Exception = exception;
+        }
+
+        public MqttApplicationMessage ApplicationMessage { get; }
+        public Exception Exception { get; }
+
+        public bool HasFailed => Exception != null;
+        public bool HasSucceeded => Exception == null;
+    }
+}
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+
+namespace MQTTnet.ManagedClient
+{
+    public interface IManagedMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher, IDisposable
+    {
+        bool IsStarted { get; }
+        bool IsConnected { get; }
+
+        event EventHandler<MqttClientConnectedEventArgs> Connected;
+        event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+
+        event EventHandler<ApplicationMessageProcessedEventArgs> ApplicationMessageProcessed;
+
+        Task StartAsync(IManagedMqttClientOptions options);
+        Task StopAsync();
+
+        Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+        Task UnsubscribeAsync(IEnumerable<string> topics);
+    }
+}
@@ -0,0 +1,14 @@
+using System;
+using MQTTnet.Client;
+
+namespace MQTTnet.ManagedClient
+{
+    public interface IManagedMqttClientOptions
+    {
+        IMqttClientOptions ClientOptions { get; }
+
+        TimeSpan AutoReconnectDelay { get; }
+
+        IManagedMqttClientStorage Storage { get; }
+    }
+}
@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace MQTTnet.ManagedClient
+{
+    public interface IManagedMqttClientStorage
+    {
+        Task SaveQueuedMessagesAsync(IList<MqttApplicationMessage> messages);
+
+        Task<IList<MqttApplicationMessage>> LoadQueuedMessagesAsync();
+    }
+}
@@ -0,0 +1,396 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.ManagedClient
+{
+    public class ManagedMqttClient : IManagedMqttClient
+    {
+        private readonly BlockingCollection<MqttApplicationMessage> _messageQueue = new BlockingCollection<MqttApplicationMessage>();
+        private readonly Dictionary<string, MqttQualityOfServiceLevel> _subscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
+        private readonly SemaphoreSlim _subscriptionsSemaphore = new SemaphoreSlim(1, 1);
+        private readonly List<string> _unsubscriptions = new List<string>();
+
+        private readonly IMqttClient _mqttClient;
+        private readonly IMqttNetLogger _logger;
+
+        private CancellationTokenSource _connectionCancellationToken;
+        private CancellationTokenSource _publishingCancellationToken;
+
+        private ManagedMqttClientStorageManager _storageManager;
+        private IManagedMqttClientOptions _options;
+
+        private bool _subscriptionsNotPushed;
+
+        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            _mqttClient.Connected += OnConnected;
+            _mqttClient.Disconnected += OnDisconnected;
+            _mqttClient.ApplicationMessageReceived += OnApplicationMessageReceived;
+        }
+
+        public bool IsConnected => _mqttClient.IsConnected;
+        public bool IsStarted => _connectionCancellationToken != null;
+
+        public event EventHandler<MqttClientConnectedEventArgs> Connected;
+        public event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+        public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
+        public event EventHandler<ApplicationMessageProcessedEventArgs> ApplicationMessageProcessed;
+        public event EventHandler SynchronizingSubscriptionsFailed;
+
+        public async Task StartAsync(IManagedMqttClientOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+            if (options.ClientOptions == null) throw new ArgumentException("The client options are not set.", nameof(options));
+
+            if (!options.ClientOptions.CleanSession)
+            {
+                throw new NotSupportedException("The managed client does not support existing sessions.");
+            }
+
+            if (_connectionCancellationToken != null) throw new InvalidOperationException("The managed client is already started.");
+
+            _options = options;
+
+            if (_options.Storage != null)
+            {
+                _storageManager = new ManagedMqttClientStorageManager(_options.Storage);
+                await _storageManager.LoadQueuedMessagesAsync().ConfigureAwait(false);
+            }
+
+            _connectionCancellationToken = new CancellationTokenSource();
+
+#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+            Task.Run(async () => await MaintainConnectionAsync(_connectionCancellationToken.Token).ConfigureAwait(false), _connectionCancellationToken.Token).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+
+            _logger.Info<ManagedMqttClient>("Started");
+        }
+
+        public Task StopAsync()
+        {
+            StopPublishing();
+            StopMaintainingConnection();
+
+            while (_messageQueue.Any())
+            {
+                _messageQueue.Take();
+            }
+
+            return Task.FromResult(0);
+        }
+
+        public async Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
+        {
+            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
+
+            foreach (var applicationMessage in applicationMessages)
+            {
+                if (_storageManager != null)
+                {
+                    await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
+                }
+
+                _messageQueue.Add(applicationMessage);
+            }
+        }
+
+        public async Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
+        {
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            await _subscriptionsSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                foreach (var topicFilter in topicFilters)
+                {
+                    _subscriptions[topicFilter.Topic] = topicFilter.QualityOfServiceLevel;
+                    _subscriptionsNotPushed = true;
+                }
+            }
+            finally
+            {
+                _subscriptionsSemaphore.Release();
+            }
+        }
+
+        public async Task UnsubscribeAsync(IEnumerable<string> topics)
+        {
+            await _subscriptionsSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                foreach (var topic in topics)
+                {
+                    if (_subscriptions.Remove(topic))
+                    {
+                        _unsubscriptions.Add(topic);
+                        _subscriptionsNotPushed = true;
+                    }
+                }
+            }
+            finally
+            {
+                _subscriptionsSemaphore.Release();
+            }
+        }
+
+        public void Dispose()
+        {
+            _messageQueue?.Dispose();
+            _subscriptionsSemaphore?.Dispose();
+            _connectionCancellationToken?.Dispose();
+            _publishingCancellationToken?.Dispose();
+        }
+
+        private async Task MaintainConnectionAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    await TryMaintainConnectionAsync(cancellationToken).ConfigureAwait(false);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<ManagedMqttClient>(exception, "Unhandled exception while maintaining connection.");
+            }
+            finally
+            {
+                await _mqttClient.DisconnectAsync().ConfigureAwait(false);
+                _logger.Info<ManagedMqttClient>("Stopped");
+            }
+        }
+
+        private async Task TryMaintainConnectionAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                var connectionState = await ReconnectIfRequiredAsync().ConfigureAwait(false);
+                if (connectionState == ReconnectionResult.NotConnected)
+                {
+                    StopPublishing();
+                    await Task.Delay(_options.AutoReconnectDelay, cancellationToken).ConfigureAwait(false);
+                    return;
+                }
+
+                if (connectionState == ReconnectionResult.Reconnected || _subscriptionsNotPushed)
+                {
+                    await SynchronizeSubscriptionsAsync().ConfigureAwait(false);
+
+                    StartPublishing();
+
+
+                    return;
+                }
+
+                if (connectionState == ReconnectionResult.StillConnected)
+                {
+                    await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            catch (MqttCommunicationException exception)
+            {
+                _logger.Warning<ManagedMqttClient>(exception, "Communication exception while maintaining connection.");
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<ManagedMqttClient>(exception, "Unhandled exception while maintaining connection.");
+            }
+        }
+
+        private async Task PublishQueuedMessagesAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    var message = _messageQueue.Take(cancellationToken);
+                    if (message == null)
+                    {
+                        continue;
+                    }
+
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        continue;
+                    }
+
+                    await TryPublishQueuedMessageAsync(message).ConfigureAwait(false);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<ManagedMqttClient>(exception, "Unhandled exception while publishing queued application messages.");
+            }
+            finally
+            {
+                _logger.Verbose<ManagedMqttClient>("Stopped publishing messages.");
+            }
+        }
+
+        private async Task TryPublishQueuedMessageAsync(MqttApplicationMessage message)
+        {
+            Exception transmitException = null;
+            try
+            {
+                await _mqttClient.PublishAsync(message).ConfigureAwait(false);
+
+                if (_storageManager != null)
+                {
+                    await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                }
+            }
+            catch (MqttCommunicationException exception)
+            {
+                transmitException = exception;
+
+                _logger.Warning<ManagedMqttClient>(exception, "Publishing application message failed.");
+
+                if (message.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
+                {
+                    _messageQueue.Add(message);
+                }
+            }
+            catch (Exception exception)
+            {
+                transmitException = exception;
+                _logger.Error<ManagedMqttClient>(exception, "Unhandled exception while publishing queued application message.");
+            }
+            finally
+            {
+                ApplicationMessageProcessed?.Invoke(this, new ApplicationMessageProcessedEventArgs(message, transmitException));
+            }
+        }
+
+        private async Task SynchronizeSubscriptionsAsync()
+        {
+            _logger.Info<ManagedMqttClient>(nameof(ManagedMqttClient), "Synchronizing subscriptions");
+
+            List<TopicFilter> subscriptions;
+            List<string> unsubscriptions;
+
+            await _subscriptionsSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                subscriptions = _subscriptions.Select(i => new TopicFilter(i.Key, i.Value)).ToList();
+
+                unsubscriptions = new List<string>(_unsubscriptions);
+                _unsubscriptions.Clear();
+
+                _subscriptionsNotPushed = false;
+            }
+            finally
+            {
+                _subscriptionsSemaphore.Release();
+            }
+            
+            if (!subscriptions.Any() && !unsubscriptions.Any())
+            {
+                return;
+            }
+
+            try
+            {
+                if (subscriptions.Any())
+                {
+                    await _mqttClient.SubscribeAsync(subscriptions).ConfigureAwait(false);
+                }
+
+                if (unsubscriptions.Any())
+                {
+                    await _mqttClient.UnsubscribeAsync(unsubscriptions).ConfigureAwait(false);
+                }
+            }
+            catch (Exception exception)
+            {
+                _logger.Warning<ManagedMqttClient>(exception, "Synchronizing subscriptions failed.");
+                _subscriptionsNotPushed = true;
+
+                SynchronizingSubscriptionsFailed?.Invoke(this, EventArgs.Empty);
+            }
+        }
+
+        private async Task<ReconnectionResult> ReconnectIfRequiredAsync()
+        {
+            if (_mqttClient.IsConnected)
+            {
+                return ReconnectionResult.StillConnected;
+            }
+
+            try
+            {
+                await _mqttClient.ConnectAsync(_options.ClientOptions).ConfigureAwait(false);
+                return ReconnectionResult.Reconnected;
+            }
+            catch (Exception)
+            {
+                return ReconnectionResult.NotConnected;
+            }
+        }
+
+        private void OnApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs eventArgs)
+        {
+            ApplicationMessageReceived?.Invoke(this, eventArgs);
+        }
+
+        private void OnDisconnected(object sender, MqttClientDisconnectedEventArgs eventArgs)
+        {
+            Disconnected?.Invoke(this, eventArgs);
+        }
+
+        private void OnConnected(object sender, MqttClientConnectedEventArgs eventArgs)
+        {
+            Connected?.Invoke(this, eventArgs);
+        }
+
+        private void StartPublishing()
+        {
+            if (_publishingCancellationToken != null)
+            {
+                StopPublishing();
+            }
+
+            var cts = new CancellationTokenSource();
+
+            _publishingCancellationToken = cts;
+
+#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+            Task.Run(async () => await PublishQueuedMessagesAsync(cts.Token).ConfigureAwait(false), cts.Token).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+        }
+
+        private void StopPublishing()
+        {
+            _publishingCancellationToken?.Cancel(false);
+            _publishingCancellationToken?.Dispose();
+            _publishingCancellationToken = null;
+        }
+
+        private void StopMaintainingConnection()
+        {
+            _connectionCancellationToken?.Cancel(false);
+            _connectionCancellationToken?.Dispose();
+            _connectionCancellationToken = null;
+        }
+    }
+}
@@ -0,0 +1,39 @@
+using System;
+using System.Threading.Tasks;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.ManagedClient
+{
+    public static class ManagedMqttClientExtensions
+    {
+        public static Task SubscribeAsync(this IManagedMqttClient managedClient, params TopicFilter[] topicFilters)
+        {
+            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
+
+            return managedClient.SubscribeAsync(topicFilters);
+        }
+
+        public static Task SubscribeAsync(this IManagedMqttClient managedClient, string topic, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return managedClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+        }
+
+        public static Task SubscribeAsync(this IManagedMqttClient managedClient, string topic)
+        {
+            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
+            if (topic == null) throw new ArgumentNullException(nameof(topic));
+
+            return managedClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).Build());
+        }
+
+        public static Task UnsubscribeAsync(this IManagedMqttClient managedClient, params string[] topicFilters)
+        {
+            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
+
+            return managedClient.UnsubscribeAsync(topicFilters);
+        }
+    }
+}
@@ -0,0 +1,14 @@
+using System;
+using MQTTnet.Client;
+
+namespace MQTTnet.ManagedClient
+{
+    public class ManagedMqttClientOptions : IManagedMqttClientOptions
+    {
+        public IMqttClientOptions ClientOptions { get; set; }
+
+        public TimeSpan AutoReconnectDelay { get; set; } = TimeSpan.FromSeconds(5);
+
+        public IManagedMqttClientStorage Storage { get; set; }
+    }
+}
@@ -0,0 +1,74 @@
+using System;
+using MQTTnet.Client;
+
+namespace MQTTnet.ManagedClient
+{
+    public class ManagedMqttClientOptionsBuilder
+    {
+        private readonly ManagedMqttClientOptions _options = new ManagedMqttClientOptions();
+        private MqttClientOptionsBuilder _clientOptionsBuilder;
+
+        public ManagedMqttClientOptionsBuilder WithAutoReconnectDelay(TimeSpan value)
+        {
+            _options.AutoReconnectDelay = value;
+            return this;
+        }
+
+        public ManagedMqttClientOptionsBuilder WithStorage(IManagedMqttClientStorage value)
+        {
+            _options.Storage = value;
+            return this;
+        }
+
+        public ManagedMqttClientOptionsBuilder WithClientOptions(IMqttClientOptions value)
+        {
+            if (_clientOptionsBuilder != null)
+            {
+                throw new InvalidOperationException("Cannot use client options builder and client options at the same time.");
+            }
+
+            _options.ClientOptions = value ?? throw new ArgumentNullException(nameof(value));
+
+            return this;
+        }
+
+        public ManagedMqttClientOptionsBuilder WithClientOptions(MqttClientOptionsBuilder builder)
+        {
+            if (_options.ClientOptions != null)
+            {
+                throw new InvalidOperationException("Cannot use client options builder and client options at the same time.");
+            }
+
+            _clientOptionsBuilder = builder;
+            return this;
+        }
+
+        public ManagedMqttClientOptionsBuilder WithClientOptions(Action<MqttClientOptionsBuilder> options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            if (_clientOptionsBuilder == null)
+            {
+                _clientOptionsBuilder = new MqttClientOptionsBuilder();
+            }
+
+            options(_clientOptionsBuilder);
+            return this;
+        }
+
+        public ManagedMqttClientOptions Build()
+        {
+            if (_clientOptionsBuilder != null)
+            {
+                _options.ClientOptions = _clientOptionsBuilder.Build();
+            }
+
+            if (_options.ClientOptions == null)
+            {
+                throw new InvalidOperationException("The ClientOptions cannot be null.");
+            }
+
+            return _options;
+        }
+    }
+}
@@ -0,0 +1,67 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.ManagedClient
+{
+    public class ManagedMqttClientStorageManager
+    {
+        private readonly List<MqttApplicationMessage> _applicationMessages = new List<MqttApplicationMessage>();
+        private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);
+        private readonly IManagedMqttClientStorage _storage;
+
+        public ManagedMqttClientStorageManager(IManagedMqttClientStorage storage)
+        {
+            _storage = storage ?? throw new ArgumentNullException(nameof(storage));
+        }
+
+        public async Task LoadQueuedMessagesAsync()
+        {
+            var loadedMessages = await _storage.LoadQueuedMessagesAsync().ConfigureAwait(false);
+            foreach (var loadedMessage in loadedMessages)
+            {
+                _applicationMessages.Add(loadedMessage);
+            }
+        }
+
+        public async Task AddAsync(MqttApplicationMessage applicationMessage)
+        {
+            await _semaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                _applicationMessages.Add(applicationMessage);
+                await SaveAsync().ConfigureAwait(false);
+            }
+            finally
+            {
+                _semaphore.Release();
+            }
+        }
+
+        public async Task RemoveAsync(MqttApplicationMessage applicationMessage)
+        {
+            await _semaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                var index = _applicationMessages.IndexOf(applicationMessage);
+                if (index == -1)
+                {
+                    return;
+                }
+
+                _applicationMessages.RemoveAt(index);
+                await SaveAsync().ConfigureAwait(false);
+            }
+            finally
+            {
+                _semaphore.Release();
+            }
+        }
+
+        private Task SaveAsync()
+        {
+            return _storage.SaveQueuedMessagesAsync(_applicationMessages);
+        }
+    }
+}
@@ -0,0 +1,9 @@
+namespace MQTTnet.ManagedClient
+{
+    public enum ReconnectionResult
+    {
+        StillConnected,
+        Reconnected,
+        NotConnected
+    }
+}
@@ -1,10 +1,15 @@
 using System;
-using MQTTnet.Core.Protocol;
+using MQTTnet.Protocol;

-namespace MQTTnet.Core
+namespace MQTTnet
 {
    public sealed class MqttApplicationMessage
    {
+        public MqttApplicationMessage()
+        {
+        }
+
+        [Obsolete("Use object initializer or _MqttApplicationMessageBuilder_ instead.")]
        public MqttApplicationMessage(string topic, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, bool retain)
        {
            Topic = topic ?? throw new ArgumentNullException(nameof(topic));
@@ -13,12 +18,12 @@ namespace MQTTnet.Core
            Retain = retain;
        }

-        public string Topic { get; }
+        public string Topic { get; set; }

-        public byte[] Payload { get; }
+        public byte[] Payload { get; set; }

-        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; }
+        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; set; }

-        public bool Retain { get; }
+        public bool Retain { get; set; }
    }
 }
@@ -0,0 +1,114 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using MQTTnet.Exceptions;
+using MQTTnet.Protocol;
+
+namespace MQTTnet
+{
+    public class MqttApplicationMessageBuilder
+    {
+        private MqttQualityOfServiceLevel _qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce;
+        private string _topic;
+        private byte[] _payload;
+        private bool _retain;
+
+        public MqttApplicationMessageBuilder WithTopic(string topic)
+        {
+            _topic = topic;
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithPayload(IEnumerable<byte> payload)
+        {
+            if (payload == null)
+            {
+                _payload = null;
+                return this;
+            }
+
+            _payload = payload.ToArray();
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithPayload(MemoryStream payload)
+        {
+            if (payload == null)
+            {
+                _payload = null;
+                return this;
+            }
+
+            if (payload.Length == 0)
+            {
+                _payload = new byte[0];
+            }
+            else
+            {
+                _payload = new byte[payload.Length - payload.Position];
+                payload.Read(_payload, 0, _payload.Length);
+            }
+
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithPayload(string payload)
+        {
+            if (payload == null)
+            {
+                _payload = null;
+                return this;
+            }
+
+            _payload = string.IsNullOrEmpty(payload) ? new byte[0] : Encoding.UTF8.GetBytes(payload);
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithQualityOfServiceLevel(MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            _qualityOfServiceLevel = qualityOfServiceLevel;
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithRetainFlag(bool value = true)
+        {
+            _retain = value;
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithAtLeastOnceQoS()
+        {
+            _qualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce;
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithAtMostOnceQoS()
+        {
+            _qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce;
+            return this;
+        }
+
+        public MqttApplicationMessageBuilder WithExactlyOnceQoS()
+        {
+            _qualityOfServiceLevel = MqttQualityOfServiceLevel.ExactlyOnce;
+            return this;
+        }
+
+        public MqttApplicationMessage Build()
+        {
+            if (string.IsNullOrEmpty(_topic))
+            {
+                throw new MqttProtocolViolationException("Topic is not set.");
+            }
+
+            return new MqttApplicationMessage
+            {
+                Topic = _topic,
+                Payload = _payload ?? new byte[0],
+                QualityOfServiceLevel = _qualityOfServiceLevel,
+                Retain = _retain
+            };
+        }
+    }
+}
@@ -0,0 +1,25 @@
+using System;
+using System.Text;
+
+namespace MQTTnet
+{
+    public static class MqttApplicationMessageExtensions
+    {
+        public static string ConvertPayloadToString(this MqttApplicationMessage applicationMessage)
+        {
+            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
+
+            if (applicationMessage.Payload == null)
+            {
+                return null;
+            }
+
+            if (applicationMessage.Payload.Length == 0)
+            {
+                return string.Empty;
+            }
+
+            return Encoding.UTF8.GetString(applicationMessage.Payload, 0, applicationMessage.Payload.Length);
+        }
+    }
+}
@@ -1,6 +1,6 @@
 using System;

-namespace MQTTnet.Core.Server
+namespace MQTTnet
 {
    public sealed class MqttApplicationMessageReceivedEventArgs : EventArgs
    {
@@ -1,13 +0,0 @@
-using MQTTnet.Core.Client;
-using MQTTnet.Implementations;
-
-namespace MQTTnet
-{
-    public class MqttClientFactory : IMqttClientFactory
-    {
-        public IMqttClient CreateMqttClient()
-        {
-            return new MqttClient(new MqttCommunicationAdapterFactory());
-        }
-    }
-}
@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using MQTTnet.Adapter;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Implementations;
+using MQTTnet.ManagedClient;
+using MQTTnet.Server;
+
+namespace MQTTnet
+{
+    public class MqttFactory : IMqttClientFactory, IMqttServerFactory
+    {
+        public IMqttClient CreateMqttClient()
+        {
+            return CreateMqttClient(new MqttNetLogger());
+        }
+
+        public IMqttClient CreateMqttClient(IMqttNetLogger logger)
+        {
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+
+            return new MqttClient(new MqttClientAdapterFactory(), logger);
+        }
+
+        public IManagedMqttClient CreateManagedMqttClient()
+        {
+            return new ManagedMqttClient(CreateMqttClient(), new MqttNetLogger());
+        }
+
+        public IManagedMqttClient CreateManagedMqttClient(IMqttNetLogger logger)
+        {
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+
+            return new ManagedMqttClient(CreateMqttClient(), logger);
+        }
+
+        public IMqttServer CreateMqttServer()
+        {
+            var logger = new MqttNetLogger();
+            return CreateMqttServer(logger);
+        }
+
+        public IMqttServer CreateMqttServer(IMqttNetLogger logger)
+        {
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+
+            return CreateMqttServer(new List<IMqttServerAdapter> { new MqttTcpServerAdapter(logger) }, logger);
+        }
+
+        public IMqttServer CreateMqttServer(IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger)
+        {
+            if (adapters == null) throw new ArgumentNullException(nameof(adapters));
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+
+            return new MqttServer(adapters, logger);
+        }
+    }
+}
@@ -1,18 +0,0 @@
-using System;
-using System.Collections.Generic;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Server;
-using MQTTnet.Implementations;
-
-namespace MQTTnet
-{
-    public class MqttServerFactory : IMqttServerFactory
-    {
-        public IMqttServer CreateMqttServer(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttServer(options, new List<IMqttServerAdapter> { new MqttServerAdapter() });
-        }
-    }
-}
@@ -0,0 +1,7 @@
+namespace MQTTnet.Packets
+{
+    public interface IMqttPacketWithIdentifier
+    {
+        ushort? PacketIdentifier { get; set; }
+    }
+}
@@ -1,4 +1,4 @@
-namespace MQTTnet.Core.Packets
+namespace MQTTnet.Packets
 {
    public abstract class MqttBasePacket
    {
@@ -1,7 +1,7 @@
-namespace MQTTnet.Core.Packets
+namespace MQTTnet.Packets
 {
    public class MqttBasePublishPacket : MqttBasePacket, IMqttPacketWithIdentifier
    {
-        public ushort PacketIdentifier { get; set; }
+        public ushort? PacketIdentifier { get; set; }
    }
 }
@@ -1,6 +1,6 @@
-using MQTTnet.Core.Protocol;
+using MQTTnet.Protocol;

-namespace MQTTnet.Core.Packets
+namespace MQTTnet.Packets
 {
    public sealed class MqttConnAckPacket : MqttBasePacket
    {
@@ -10,7 +10,7 @@ namespace MQTTnet.Core.Packets

        public override string ToString()
        {
-            return nameof(MqttConnAckPacket) + ": [ConnectReturnCode=" + ConnectReturnCode + "] [IsSessionPresent=" + IsSessionPresent + "]";
+            return "ConnAck: [ConnectReturnCode=" + ConnectReturnCode + "] [IsSessionPresent=" + IsSessionPresent + "]";
        }
    }
 }
@@ -1,6 +1,6 @@
-using MQTTnet.Core.Serializer;
+using MQTTnet.Serializer;

-namespace MQTTnet.Core.Packets
+namespace MQTTnet.Packets
 {
    public sealed class MqttConnectPacket : MqttBasePacket
    {
@@ -20,7 +20,7 @@ namespace MQTTnet.Core.Packets

        public override string ToString()
        {
-            return nameof(MqttConnectPacket) + ": [ClientId=" + ClientId + "] [Username=" + Username + "] [Password=" + Password + "] [KeepAlivePeriod=" + KeepAlivePeriod + "] [CleanSession=" + CleanSession + "]";
+            return "Connect: [ClientId=" + ClientId + "] [Username=" + Username + "] [Password=" + Password + "] [KeepAlivePeriod=" + KeepAlivePeriod + "] [CleanSession=" + CleanSession + "]";
        }
    }
 }
--- a/Show More
+++ b/Show More