Update documents

Reference to MQTT Tester - updated

.bettercodehub.yml

@@ -0,0 +1,8 @@
+exclude:
+- /Frameworks/.*
+- /MQTTnet.TestApp.NetCore/Program.cs
+- /Tests/MQTTnet.TestApp.NetFramework/.*
+- /Tests/MQTTnet.TestApp.UniversalWindows/.*
+component_depth: 1
+languages:
+- csharp

.gitignore

@@ -1,5 +1,7 @@
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
+##
+## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore
 
 # User-specific files
 *.suo
@@ -15,12 +17,12 @@
 [Dd]ebugPublic/
 [Rr]elease/
 [Rr]eleases/
-[Xx]64/
+x64/
-[Xx]86/
+x86/
-[Bb]uild/
 bld/
 [Bb]in/
 [Oo]bj/
+[Ll]og/
 
 # Visual Studio 2015 cache/options directory
 .vs/
@@ -40,9 +42,11 @@ TestResult.xml
 [Rr]eleasePS/
 dlldata.c
 
-# DNX
+# .NET Core
 project.lock.json
+project.fragment.lock.json
 artifacts/
+**/Properties/launchSettings.json
 
 *_i.c
 *_p.c
@@ -81,6 +85,7 @@ ipch/
 *.sdf
 *.cachefile
 *.VC.db
+*.VC.VC.opendb
 
 # Visual Studio profiler
 *.psess
@@ -108,6 +113,10 @@ _TeamCity*
 # DotCover is a Code Coverage Tool
 *.dotCover
 
+# Visual Studio code coverage results
+*.coverage
+*.coveragexml
+
 # NCrunch
 _NCrunch_*
 .*crunch*.local.xml
@@ -139,13 +148,16 @@ publish/
 # Publish Web Output
 *.[Pp]ublish.xml
 *.azurePubxml
-
+# TODO: Comment the next line if you want to checkin your web deploy settings
-# TODO: Un-comment the next line if you do not want to checkin 
+# but database connection strings (with potential passwords) will be unencrypted
-# your web deploy settings because they may include unencrypted
+*.pubxml
-# passwords
-#*.pubxml
 *.publishproj
 
+# Microsoft Azure Web App publish settings. Comment the next line if you want to
+# checkin your Azure Web App publish settings, but sensitive information contained
+# in these scripts will be unencrypted
+PublishScripts/
+
 # NuGet Packages
 *.nupkg
 # The packages folder can be ignored because of Package Restore
@@ -154,7 +166,7 @@ publish/
 !**/packages/build/
 # Uncomment if necessary however generally it will be regenerated when needed
 #!**/packages/repositories.config
-# NuGet v3's project.json files produces more ignoreable files
+# NuGet v3's project.json files produces more ignorable files
 *.nuget.props
 *.nuget.targets
 
@@ -166,12 +178,11 @@ csx/
 ecf/
 rcf/
 
-# Microsoft Azure ApplicationInsights config file
+# Windows Store app package directories and files
-ApplicationInsights.config
-
-# Windows Store app package directory
 AppPackages/
 BundleArtifacts/
+Package.StoreAssociation.xml
+_pkginfo.txt
 
 # Visual Studio cache files
 # files ending in .cache can be ignored
@@ -181,16 +192,19 @@ BundleArtifacts/
 
 # Others
 ClientBin/
-[Ss]tyle[Cc]op.*
 ~$*
 *~
 *.dbmdl
 *.dbproj.schemaview
-*.pfx
+*.jfm
+# *.pfx
 *.publishsettings
-node_modules/
 orleans.codegen.cs
 
+# Since there are multiple workflows, uncomment next line to ignore bower_components
+# (https://github.com/github/gitignore/pull/1529#issuecomment-104372622)
+#bower_components/
+
 # RIA/Silverlight projects
 Generated_Code/
 
@@ -205,6 +219,7 @@ UpgradeLog*.htm
 # SQL Server files
 *.mdf
 *.ldf
+*.ndf
 
 # Business Intelligence projects
 *.rdl.data
@@ -219,6 +234,10 @@ FakesAssemblies/
 
 # Node.js Tools for Visual Studio
 .ntvs_analysis.dat
+node_modules/
+
+# Typescript v1 declaration files
+typings/
 
 # Visual Studio 6 build log
 *.plg
@@ -226,6 +245,9 @@ FakesAssemblies/
 # Visual Studio 6 workspace options file
 *.opt
 
+# Visual Studio 6 auto-generated workspace file (contains which files were open etc.)
+*.vbw
+
 # Visual Studio LightSwitch build output
 **/*.HTMLClient/GeneratedArtifacts
 **/*.DesktopClient/GeneratedArtifacts
@@ -234,13 +256,38 @@ FakesAssemblies/
 **/*.Server/ModelManifest.xml
 _Pvt_Extensions
 
-# LightSwitch generated files
-GeneratedArtifacts/
-ModelManifest.xml
-
 # Paket dependency manager
 .paket/paket.exe
+paket-files/
 
 # FAKE - F# Make
 .fake/
-nuget.exe
+
+# JetBrains Rider
+.idea/
+*.sln.iml
+
+# CodeRush
+.cr/
+
+# Python Tools for Visual Studio (PTVS)
+__pycache__/
+*.pyc
+
+# Cake - Uncomment if you are using it
+# tools/**
+# !tools/packages.config
+
+# Telerik's JustMock configuration file
+*.jmconfig
+
+# BizTalk build output
+*.btp.cs
+*.btm.cs
+*.odx.cs
+*.xsd.cs
+
+
+Build/nuget.exe
+*.js
+*.map

.travis.yml

@@ -0,0 +1,10 @@
+language: csharp
+solution: MQTTnet.sln
+
+matrix:
+  include:
+    - dotnet: 2.0.0
+      mono: none
+      dist: trusty
+      env: DOTNETCORE=1  # optional, can be used to take different code paths in your script
+    - mono: latest

Build/MQTTnet.AspNetCore.nuspec

@@ -0,0 +1,28 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>MQTTnet.AspNetCore</id>
+    <version>2.5.3</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 2.5.3.
+    </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="2.5.3-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>

Build/MQTTnet.nuspec

@@ -0,0 +1,69 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>MQTTnet</id>
+    <version>2.5.3</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 high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
+    <releaseNotes>* [Core] Removed all dependencies to other libraries (BREAKING CHANGE!).
+* [Core] Updated SDK libraries.
+* [Client] Fixed broken support for WebSocketSecure connections (Thanks to @StAI).
+    </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="netstandard1.3">
+        <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="5.4.1" />
+      </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.Core.*" target="lib\netstandard2.0\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\netstandard2.0\MQTTnet.*" target="lib\netstandard2.0\"/>
+
+    <!-- Universal Windows -->
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\uap10.0\MQTTnet.Core.*" target="lib\uap10.0\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\uap10.0\MQTTnet.*" target="lib\uap10.0\"/>
+
+    <!-- .NET Framework -->
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net452\MQTTnet.Core.*" target="lib\net452\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net452\MQTTnet.*" target="lib\net452\"/>
+
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net461\MQTTnet.Core.*" target="lib\net461\"/>
+    <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net461\MQTTnet.*" target="lib\net461\"/>
+    
+  </files>
+</package>

Build/build.ps1

@@ -0,0 +1,23 @@
+param([string]$assemblyVersion, [string]$nugetVersion)
+
+if ([string]::IsNullOrEmpty($version)) {$version = "0.0.1"}
+
+$vswhere = ${Env:\ProgramFiles(x86)} + '\Microsoft Visual Studio\Installer\vswhere'
+
+$path = &$vswhere -latest -products * -requires Microsoft.Component.MSBuild -property installationPath
+if ($path) {
+    $msbuild = join-path $path 'MSBuild\15.0\Bin\MSBuild.exe'
+
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    &$msbuild ..\Frameworks\MQTTnet.Netstandard\MQTTnet.Netstandard.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+    
+	&$msbuild ..\Frameworks\MQTTnet.AspNetCore\MQTTnet.AspNetCore.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m
+
+    Remove-Item .\NuGet -Force -Recurse
+    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
+}

Frameworks/MQTTnet.AspnetCore/ApplicationBuilderExtensions.cs

@@ -0,0 +1,52 @@
+using System;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using MQTTnet.Core.Server;
+using System.Linq;
+
+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;
+        }
+    }
+}

Frameworks/MQTTnet.AspnetCore/MQTTnet.AspnetCore.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <AssemblyVersion>2.5.2.0</AssemblyVersion>
+    <FileVersion>2.5.2.0</FileVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="2.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\MQTTnet.Netstandard\MQTTnet.NetStandard.csproj" />
+  </ItemGroup>
+
+</Project>

Frameworks/MQTTnet.AspnetCore/MqttHostedServer.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Hosting;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public class MqttHostedServer : MqttServer, IHostedService
+    {
+        private readonly MqttServerOptions _options;
+
+        public MqttHostedServer(MqttServerOptions 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();
+        }
+    }
+}

Frameworks/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Serializer;
+using MQTTnet.Core.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public class MqttWebSocketServerAdapter : IMqttServerAdapter, IDisposable
+    {
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public Task StartAsync(MqttServerOptions 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();
+        }
+    }
+}

Frameworks/MQTTnet.AspnetCore/MqttWebSocketServerChannel.cs

@@ -0,0 +1,60 @@
+using System;
+using System.IO;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.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;
+        }
+    }
+}

Frameworks/MQTTnet.AspnetCore/ServiceCollectionExtensions.cs

@@ -0,0 +1,28 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class ServiceCollectionExtensions
+    {
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions 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<IMqttServerAdapter>(s => s.GetService<MqttWebSocketServerAdapter>());
+
+            return services;
+        }
+    }
+}

Frameworks/MQTTnet.NetCoreApp/MQTTnet.NetCoreApp.csproj

@@ -1,34 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <TargetFramework>netcoreapp1.1</TargetFramework>
-    <Authors>Christian Kratky</Authors>
-    <Company>Christian Kratky</Company>
-    <Product>MQTTnet</Product>
-    <Description>MQTTnet is a .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</Description>
-    <Copyright>Copyright © Christian Kratky 2016-2017</Copyright>
-    <Version>2.1.1.0</Version>
-    <AssemblyVersion>2.1.1.0</AssemblyVersion>
-    <FileVersion>2.1.1.0</FileVersion>
-    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
-    <AssemblyName>MQTTnet</AssemblyName>
-    <RootNamespace>MQTTnet</RootNamespace>
-    <PackageId>MQTTnet.NetCore</PackageId>
-    <PackageProjectUrl>https://github.com/chkr1011/MQTTnet</PackageProjectUrl>
-    <RepositoryUrl>https://github.com/chkr1011/MQTTnet</RepositoryUrl>
-    <PackageTags>MQTT MQTTClient MQTTServer MQTTBroker Broker</PackageTags>
-    <PackageIconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</PackageIconUrl>
-    <PackageLicenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</PackageLicenseUrl>
-  </PropertyGroup>
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|AnyCPU'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|x64'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|x86'" />
-
-  <ItemGroup>
-    <ProjectReference Include="..\..\MQTTnet.Core\MQTTnet.Core.csproj" />
-  </ItemGroup>
-
-</Project>

Frameworks/MQTTnet.NetCoreApp/MqttClientFactory.cs

@@ -1,17 +0,0 @@
-using System;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet
-{
-    public class MqttClientFactory
-    {
-        public MqttClient CreateMqttClient(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttClient(options, new MqttChannelCommunicationAdapter(new MqttTcpChannel(), new DefaultMqttV311PacketSerializer()));
-        }
-    }
-}

Frameworks/MQTTnet.NetCoreApp/MqttServerAdapter.cs

@@ -1,56 +0,0 @@
-using System;
-using System.Net;
-using System.Net.Sockets;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public sealed class MqttServerAdapter : IMqttServerAdapter, IDisposable
-    {
-        private CancellationTokenSource _cancellationTokenSource;
-        private Socket _socket;
-
-        public event EventHandler<MqttClientConnectedEventArgs> ClientConnected;
-
-        public void Start(MqttServerOptions options)
-        {
-            if (_socket != null) throw new InvalidOperationException("Server is already started.");
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-            _socket.Bind(new IPEndPoint(IPAddress.Any, options.Port));
-            _socket.Listen(options.ConnectionBacklog);
-            
-            Task.Run(async () => await AcceptConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-        }
-
-        public void Stop()
-        {
-            _cancellationTokenSource?.Dispose();
-            _cancellationTokenSource = null;
-
-            _socket?.Dispose();
-            _socket = null;
-        }
-
-        public void Dispose()
-        {
-            Stop();
-        }
-
-        private async Task AcceptConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                var clientSocket = await _socket.AcceptAsync();
-                var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket), new DefaultMqttV311PacketSerializer());    
-                ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
-            }
-        }
-    }
-}

Frameworks/MQTTnet.NetCoreApp/MqttServerFactory.cs

@@ -1,15 +0,0 @@
-using System;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public class MqttServerFactory
-    {
-        public MqttServer CreateMqttServer(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttServer(options, new MqttServerAdapter());
-        }
-    }
-}

Frameworks/MQTTnet.NetCoreApp/MqttTcpChannel.cs

@@ -1,81 +0,0 @@
-using System;
-using System.Net.Sockets;
-using System.Threading.Tasks;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Exceptions;
-
-namespace MQTTnet
-{
-    public class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
-    {
-        private readonly Socket _socket;
-
-        public MqttTcpChannel()
-        {
-            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-        }
-
-        public MqttTcpChannel(Socket socket)
-        {
-            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
-        }
-
-        public async Task ConnectAsync(MqttClientOptions options)
-        {
-            try
-            {
-                await _socket.ConnectAsync(options.Server, options.Port);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task DisconnectAsync()
-        {
-            try
-            {
-                _socket.Dispose();
-                await Task.FromResult(0);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task WriteAsync(byte[] buffer)
-        {
-            if (buffer == null) throw new ArgumentNullException(nameof(buffer));
-
-            try
-            {
-                await _socket.SendAsync(new ArraySegment<byte>(buffer), SocketFlags.None);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task ReadAsync(byte[] buffer)
-        {
-            try
-            {
-                var buffer2 = new ArraySegment<byte>(buffer);
-                await _socket.ReceiveAsync(buffer2, SocketFlags.None);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public void Dispose()
-        {
-            _socket?.Dispose();
-        }
-    }
-}

Frameworks/MQTTnet.NetFramework/MQTTnet.NetFramework.csproj

@@ -1,123 +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="MqttClientFactory.cs" />
-    <Compile Include="MqttServerAdapter.cs" />
-    <Compile Include="MqttServerFactory.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="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>

Frameworks/MQTTnet.NetFramework/MqttClientFactory.cs

@@ -1,17 +0,0 @@
-using System;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet
-{
-    public class MqttClientFactory
-    {
-        public MqttClient CreateMqttClient(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttClient(options, new MqttChannelCommunicationAdapter(new MqttTcpChannel(), new DefaultMqttV311PacketSerializer()));
-        }
-    }
-}

Frameworks/MQTTnet.NetFramework/MqttServerAdapter.cs

@@ -1,56 +0,0 @@
-using System;
-using System.Net;
-using System.Net.Sockets;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public sealed class MqttServerAdapter : IMqttServerAdapter, IDisposable
-    {
-        private CancellationTokenSource _cancellationTokenSource;
-        private Socket _socket;
-
-        public event EventHandler<MqttClientConnectedEventArgs> ClientConnected;
-
-        public void Start(MqttServerOptions options)
-        {
-            if (_socket != null) throw new InvalidOperationException("Server is already started.");
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-            _socket.Bind(new IPEndPoint(IPAddress.Any, options.Port));
-            _socket.Listen(options.ConnectionBacklog);
-            
-            Task.Run(async () => await AcceptConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
-        }
-
-        public void Stop()
-        {
-            _cancellationTokenSource?.Dispose();
-            _cancellationTokenSource = null;
-
-            _socket?.Dispose();
-            _socket = null;
-        }
-
-        public void Dispose()
-        {
-            Stop();
-        }
-
-        private async Task AcceptConnectionsAsync(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                var clientSocket = await Task.Factory.FromAsync(_socket.BeginAccept, _socket.EndAccept, null);
-                var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket), new DefaultMqttV311PacketSerializer());    
-                ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
-            }
-        }
-    }
-}

Frameworks/MQTTnet.NetFramework/MqttServerFactory.cs

@@ -1,15 +0,0 @@
-using System;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public class MqttServerFactory
-    {
-        public MqttServer CreateMqttServer(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttServer(options, new MqttServerAdapter());
-        }
-    }
-}

Frameworks/MQTTnet.NetFramework/MqttTcpChannel.cs

@@ -1,85 +0,0 @@
-using System;
-using System.Net.Sockets;
-using System.Threading.Tasks;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Exceptions;
-
-namespace MQTTnet
-{
-    public class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
-    {
-        private readonly Socket _socket;
-
-        public MqttTcpChannel()
-        {
-            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-        }
-
-        public MqttTcpChannel(Socket socket)
-        {
-            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
-        }
-
-        public async Task ConnectAsync(MqttClientOptions options)
-        {
-            try
-            {
-                await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, options.Server, options.Port, null);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task DisconnectAsync()
-        {
-            try
-            {
-                await Task.Factory.FromAsync(_socket.BeginDisconnect, _socket.EndDisconnect, true, null);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task WriteAsync(byte[] buffer)
-        {
-            if (buffer == null) throw new ArgumentNullException(nameof(buffer));
-
-            try
-            {
-                await Task.Factory.FromAsync(
-                    // ReSharper disable once AssignNullToNotNullAttribute
-                    _socket.BeginSend(buffer, 0, buffer.Length, SocketFlags.None, null, null),
-                    _socket.EndSend);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public async Task ReadAsync(byte[] buffer)
-        {
-            try
-            {
-                await Task.Factory.FromAsync(
-                    // ReSharper disable once AssignNullToNotNullAttribute
-                    _socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, null, null),
-                    _socket.EndReceive);
-            }
-            catch (SocketException exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-        }
-
-        public void Dispose()
-        {
-            _socket?.Dispose();
-        }
-    }
-}

Frameworks/MQTTnet.NetFramework/Properties/AssemblyInfo.cs

@@ -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("2.1.1.0")]
-[assembly: AssemblyFileVersion("2.1.1.0")]

Frameworks/MQTTnet.NetStandard/Diagnostics/MqttNetConsoleLogger.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Text;
+using MQTTnet.Core.Diagnostics;
+
+namespace MQTTnet.Diagnostics
+{
+    public static class MqttNetConsoleLogger
+    {
+        private static readonly object Lock = new object();
+
+        public static void ForwardToConsole()
+        {
+            MqttNetGlobalLog.LogMessagePublished -= PrintToConsole;
+            MqttNetGlobalLog.LogMessagePublished += PrintToConsole;
+        }
+
+        private static void PrintToConsole(object sender, MqttNetLogMessagePublishedEventArgs e)
+        {
+            var output = new StringBuilder();
+            output.AppendLine($">> [{e.TraceMessage.Timestamp:O}] [{e.TraceMessage.ThreadId}] [{e.TraceMessage.Source}] [{e.TraceMessage.Level}]: {e.TraceMessage.Message}");
+            if (e.TraceMessage.Exception != null)
+            {
+                output.AppendLine(e.TraceMessage.Exception.ToString());
+            }
+
+            lock (Lock)
+            {
+                var backupColor = Console.ForegroundColor;
+                switch (e.TraceMessage.Level)
+                {
+                    case MqttNetLogLevel.Error:
+                        Console.ForegroundColor = ConsoleColor.Red;
+                        break;
+                    case MqttNetLogLevel.Warning:
+                        Console.ForegroundColor = ConsoleColor.Yellow;
+                        break;
+                    case MqttNetLogLevel.Info:
+                        Console.ForegroundColor = ConsoleColor.Green;
+                        break;
+                    case MqttNetLogLevel.Verbose:
+                        Console.ForegroundColor = ConsoleColor.Gray;
+                        break;
+                }
+
+                Console.Write(output);
+                Console.ForegroundColor = backupColor;
+            }
+        }
+    }
+}

Frameworks/MQTTnet.NetStandard/Diagnostics/TargetFrameworkInfoProvider.cs

@@ -0,0 +1,23 @@
+namespace MQTTnet
+{
+    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
+            }
+        }
+    }
+}

Frameworks/MQTTnet.NetStandard/Implementations/MqttClientAdapterFactory.cs

@@ -0,0 +1,26 @@
+using System;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Client;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Implementations
+{
+    public class MqttClientAdapterFactory : IMqttClientAdapterFactory
+    {
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientChannelOptions options, IMqttNetLogger logger)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            switch (options)
+            {
+                case MqttClientTcpOptions tcpOptions:
+                    return new MqttChannelAdapter(new MqttTcpChannel(tcpOptions), new MqttPacketSerializer(), logger);
+                case MqttClientWebSocketOptions webSocketOptions:
+                    return new MqttChannelAdapter(new MqttWebSocketChannel(webSocketOptions), new MqttPacketSerializer(), logger);
+                default:
+                    throw new NotSupportedException();
+            }
+        }
+    }
+}

Frameworks/MQTTnet.NetStandard/Implementations/MqttServerAdapter.Uwp.cs

@@ -0,0 +1,75 @@
+#if WINDOWS_UWP
+using System;
+using System.Threading.Tasks;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Server;
+using Windows.Networking.Sockets;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Implementations
+{
+    public class MqttServerAdapter : IMqttServerAdapter, IDisposable
+    {
+        private readonly IMqttNetLogger _logger;
+        private StreamSocketListener _defaultEndpointSocket;
+
+        public MqttServerAdapter(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public async Task StartAsync(MqttServerOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            if (_defaultEndpointSocket != null) throw new InvalidOperationException("Server is already started.");
+            
+            if (options.DefaultEndpointOptions.IsEnabled)
+            {
+                _defaultEndpointSocket = new StreamSocketListener();
+                await _defaultEndpointSocket.BindServiceNameAsync(options.GetDefaultEndpointPort().ToString(), SocketProtectionLevel.PlainSocket);
+                _defaultEndpointSocket.ConnectionReceived += AcceptDefaultEndpointConnectionsAsync;
+            }
+
+            if (options.TlsEndpointOptions.IsEnabled)
+            {
+                throw new NotSupportedException("TLS servers are not supported for UWP apps.");
+            }
+        }
+
+        public Task StopAsync()
+        {
+            if (_defaultEndpointSocket != null)
+            {
+                _defaultEndpointSocket.ConnectionReceived -= AcceptDefaultEndpointConnectionsAsync;
+            }
+
+            _defaultEndpointSocket?.Dispose();
+            _defaultEndpointSocket = null;
+
+            return Task.FromResult(0);
+        }
+
+        public void Dispose()
+        {
+            StopAsync();
+        }
+
+        private void AcceptDefaultEndpointConnectionsAsync(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
+        {
+            try
+            {
+                var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(args.Socket), new MqttPacketSerializer(), _logger);
+                ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<MqttServerAdapter>(exception, "Error while accepting connection at default endpoint.");
+            }
+        }
+    }
+}
+#endif

Frameworks/MQTTnet.NetStandard/Implementations/MqttServerAdapter.cs

@@ -0,0 +1,147 @@
+#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.Core.Adapter;
+using MQTTnet.Core.Server;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Implementations
+{
+    public class MqttServerAdapter : IMqttServerAdapter, IDisposable
+    {
+        private readonly IMqttNetLogger _logger;
+
+        private CancellationTokenSource _cancellationTokenSource;
+        private Socket _defaultEndpointSocket;
+        private Socket _tlsEndpointSocket;
+        private X509Certificate2 _tlsCertificate;
+
+        public MqttServerAdapter(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public Task StartAsync(MqttServerOptions 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(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);
+                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(IPAddress.Any, options.GetTlsEndpointPort()));
+                _tlsEndpointSocket.Listen(options.ConnectionBacklog);
+
+                Task.Run(() => AcceptTlsEndpointConnectionsAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
+            }
+
+            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 (Exception exception)
+                {
+                    _logger.Error<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
+                {
+#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 (Exception exception)
+                {
+                    _logger.Error<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);
+                }
+            }
+        }
+    }
+}
+#endif

Frameworks/MQTTnet.NetStandard/Implementations/MqttTcpChannel.Uwp.cs

@@ -0,0 +1,133 @@
+#if WINDOWS_UWP
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using System.Threading.Tasks;
+using Windows.Networking;
+using Windows.Networking.Sockets;
+using Windows.Security.Cryptography.Certificates;
+using MQTTnet.Core.Channel;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Implementations
+{
+    public sealed class MqttTcpChannel : IMqttChannel, IDisposable
+    {
+        private readonly MqttClientTcpOptions _options;
+        private StreamSocket _socket;
+
+        public MqttTcpChannel(MqttClientTcpOptions options)
+        {
+            _options = options ?? throw new ArgumentNullException(nameof(options));
+        }
+
+        public MqttTcpChannel(StreamSocket socket)
+        {
+            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
+
+            CreateStreams();
+        }
+
+        public Stream SendStream { get; private set; }
+        public Stream ReceiveStream { get; private set; }
+
+        public static Func<MqttClientTcpOptions, IEnumerable<ChainValidationResult>> CustomIgnorableServerCertificateErrorsResolver { get; set; }
+
+        public async Task ConnectAsync()
+        {
+            if (_socket == null)
+            {
+                _socket = new StreamSocket();
+            }
+
+            if (!_options.TlsOptions.UseTls)
+            {
+                await _socket.ConnectAsync(new HostName(_options.Server), _options.GetPort().ToString());
+            }
+            else
+            {
+                _socket.Control.ClientCertificate = LoadCertificate(_options);
+
+                foreach (var ignorableChainValidationResult in ResolveIgnorableServerCertificateErrors())
+                {
+                    _socket.Control.IgnorableServerCertificateErrors.Add(ignorableChainValidationResult);
+                }
+
+                await _socket.ConnectAsync(new HostName(_options.Server), _options.GetPort().ToString(), SocketProtectionLevel.Tls12);
+            }
+
+            CreateStreams();
+        }
+
+        public Task DisconnectAsync()
+        {
+            Dispose();
+            return Task.FromResult(0);
+        }
+
+        public void Dispose()
+        {
+            SendStream?.Dispose();
+            SendStream = null;
+
+            ReceiveStream?.Dispose();
+            ReceiveStream = null;
+
+            _socket?.Dispose();
+            _socket = null;
+        }
+
+        private void CreateStreams()
+        {
+            SendStream = _socket.OutputStream.AsStreamForWrite();
+            ReceiveStream = _socket.InputStream.AsStreamForRead();
+        }
+
+        private static Certificate LoadCertificate(MqttClientTcpOptions options)
+        {
+            if (options.TlsOptions.Certificates == null || !options.TlsOptions.Certificates.Any())
+            {
+                return null;
+            }
+
+            if (options.TlsOptions.Certificates.Count > 1)
+            {
+                throw new NotSupportedException("Only one client certificate is supported for UWP.");
+            }
+
+            return new Certificate(options.TlsOptions.Certificates.First().AsBuffer());
+        }
+
+        private IEnumerable<ChainValidationResult> ResolveIgnorableServerCertificateErrors()
+        {
+            if (CustomIgnorableServerCertificateErrorsResolver != null)
+            {
+                return CustomIgnorableServerCertificateErrorsResolver(_options);
+            }
+
+            var result = new List<ChainValidationResult>();
+
+            if (_options.TlsOptions.IgnoreCertificateRevocationErrors)
+            {
+                result.Add(ChainValidationResult.RevocationInformationMissing);
+                //_socket.Control.IgnorableServerCertificateErrors.Add(ChainValidationResult.Revoked); Not supported.
+                result.Add(ChainValidationResult.RevocationFailure);
+            }
+
+            if (_options.TlsOptions.IgnoreCertificateChainErrors)
+            {
+                result.Add(ChainValidationResult.IncompleteChain);
+            }
+
+            if (_options.TlsOptions.AllowUntrustedCertificates)
+            {
+                result.Add(ChainValidationResult.Untrusted);
+            }
+
+            return result;
+        }
+    }
+}
+#endif

Frameworks/MQTTnet.NetStandard/Implementations/MqttTcpChannel.cs

@@ -0,0 +1,158 @@
+#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;
+
+namespace MQTTnet.Implementations
+{
+    public sealed class MqttTcpChannel : IMqttChannel, IDisposable
+    {
+        private readonly MqttClientTcpOptions _options;
+
+        //todo: this can be used with min dependency NetStandard1.6
+#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.
+#endif
+
+        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 static Func<X509Certificate, X509Chain, SslPolicyErrors, MqttClientTcpOptions, bool> CustomCertificateValidationCallback { get; set; }
+
+        public async Task ConnectAsync()
+        {
+            if (_socket == null)
+            {
+                _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+            }
+
+            //todo: else brach can be used with min dependency NET46
+#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);
+                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()
+        {
+            _socket?.Dispose();
+            _socket = null;
+
+            _sslStream?.Dispose();
+            _sslStream = null;
+        }
+
+        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(MqttClientTcpOptions 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;
+        }
+
+        private void CreateStreams(Socket socket, Stream sslStream)
+        {
+            var stream = 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
+
+            //todo: if branch can be used with min dependency NetStandard1.6
+#if NET452 || NET461
+            SendStream = new BufferedStream(stream, BufferSize);
+            ReceiveStream = new BufferedStream(stream, BufferSize);
+#else
+            SendStream = stream;
+            ReceiveStream = stream;
+#endif
+        }
+
+    }
+}
+#endif

Frameworks/MQTTnet.NetStandard/Implementations/MqttWebSocketChannel.cs

@@ -0,0 +1,103 @@
+using MQTTnet.Core.Channel;
+using MQTTnet.Core.Client;
+using System;
+using System.IO;
+using System.Net.WebSockets;
+using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Implementations
+{
+    public sealed class MqttWebSocketChannel : IMqttChannel, IDisposable
+    {
+        // 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;
+
+        public MqttWebSocketChannel(MqttClientWebSocketOptions options)
+        {
+            _options = options ?? throw new ArgumentNullException(nameof(options));
+        }
+
+        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) && !uri.StartsWith("wss://", StringComparison.OrdinalIgnoreCase))
+            {
+                if (_options.TlsOptions?.UseTls == false)
+                {
+                    uri = "ws://" + uri;
+                }
+                else
+                {
+                    uri = "wss://" + uri;
+                }
+            }
+
+            _webSocket = new ClientWebSocket();
+            
+            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()
+        {
+            if (_webSocket == null)
+            {
+                return;
+            }
+
+            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();
+            _webSocket = null;
+        }
+    }
+}

Frameworks/MQTTnet.NetStandard/Implementations/WebSocketStream.cs

@@ -0,0 +1,129 @@
+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.Core.Exceptions;
+
+namespace MQTTnet.Implementations
+{
+    public class WebSocketStream : Stream
+    {
+        private readonly WebSocket _webSocket;
+        private readonly byte[] _chunkBuffer = new byte[MqttWebSocketChannel.BufferSize];
+        private readonly Queue<byte> _buffer = new Queue<byte>(MqttWebSocketChannel.BufferSize);
+
+        public WebSocketStream(WebSocket webSocket)
+        {
+            _webSocket = webSocket ?? throw new ArgumentNullException(nameof(webSocket));
+        }
+
+        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 void Flush()
+        {
+        }
+
+        public override Task FlushAsync(CancellationToken cancellationToken)
+        {
+            return Task.FromResult(0);
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            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++;
+            }
+
+            if (count == 0)
+            {
+                return bytesRead;
+            }
+            
+            while (_webSocket.State == WebSocketState.Open)
+            {
+                await FetchChunkAsync(cancellationToken);
+
+                while (count > 0 && _buffer.Any())
+                {
+                    buffer[offset++] = _buffer.Dequeue();
+                    count--;
+                    bytesRead++;
+                }
+
+                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();
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+
+        private async Task FetchChunkAsync(CancellationToken cancellationToken)
+        {
+            var response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(_chunkBuffer, 0, _chunkBuffer.Length), cancellationToken).ConfigureAwait(false);
+
+            for (var i = 0; i < response.Count; i++)
+            {
+                var @byte = _chunkBuffer[i];
+                _buffer.Enqueue(@byte);
+            }
+
+            if (response.MessageType == WebSocketMessageType.Close)
+            {
+                await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+}

Frameworks/MQTTnet.NetStandard/MQTTnet.Netstandard.csproj

@@ -0,0 +1,62 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;net452;net461;uap10.0</TargetFrameworks>
+    <AssemblyName>MQTTnet</AssemblyName>
+    <RootNamespace>MQTTnet</RootNamespace>
+    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
+    <DebugType>Full</DebugType>
+    <AssemblyVersion>2.5.3.0</AssemblyVersion>
+    <FileVersion>2.5.3.0</FileVersion>
+    <Version>0.0.0.0</Version>
+    <Company />
+    <Product />
+    <Description />
+    <Authors />
+    <PackageId />
+  </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>
+    <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>
+
+  <ItemGroup Condition="'$(TargetFramework)'=='netstandard2.0'">
+    <PackageReference Include="System.Net.Security" Version="4.3.2" />
+    <PackageReference Include="System.Net.WebSockets" Version="4.3.0" />
+    <PackageReference Include="System.Net.WebSockets.Client" Version="4.3.1" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(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>

Frameworks/MQTTnet.NetStandard/MqttFactory.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Client;
+using MQTTnet.Implementations;
+using MQTTnet.Core.ManagedClient;
+using MQTTnet.Core.Server;
+using MQTTnet.Core.Diagnostics;
+
+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(new List<IMqttServerAdapter> { new MqttServerAdapter(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);
+        }
+    }
+}

Frameworks/MQTTnet.UniversalWindows/MqttClientFactory.cs

@@ -1,17 +0,0 @@
-using System;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet
-{
-    public class MqttClientFactory
-    {
-        public MqttClient CreateMqttClient(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttClient(options, new MqttChannelCommunicationAdapter(new MqttTcpChannel(), new DefaultMqttV311PacketSerializer()));
-        }
-    }
-}

Frameworks/MQTTnet.UniversalWindows/MqttServerAdapter.cs

@@ -1,54 +0,0 @@
-using System;
-using System.Threading;
-using Windows.Networking.Sockets;
-using MQTTnet.Core.Adapter;
-using MQTTnet.Core.Serializer;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public sealed class MqttServerAdapter : IMqttServerAdapter, IDisposable
-    {
-        private CancellationTokenSource _cancellationTokenSource;
-        private StreamSocketListener _socket;
-
-        public event EventHandler<MqttClientConnectedEventArgs> ClientConnected;
-
-        public void Start(MqttServerOptions options)
-        {
-            if (_socket != null) throw new InvalidOperationException("Server is already started.");
-
-            _cancellationTokenSource = new CancellationTokenSource();
-
-            _socket = new StreamSocketListener();
-            _socket.BindServiceNameAsync(options.Port.ToString()).AsTask().Wait();
-            _socket.ConnectionReceived += ConnectionReceived;
-        }
-
-        private void ConnectionReceived(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
-        {
-            var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(args.Socket), new DefaultMqttV311PacketSerializer());
-
-            var identifier = $"{args.Socket.Information.RemoteAddress}:{args.Socket.Information.RemotePort}";
-            ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(identifier, clientAdapter));
-        }
-
-        public void Stop()
-        {
-            _cancellationTokenSource?.Dispose();
-
-            if (_socket != null)
-            {
-                _socket.ConnectionReceived -= ConnectionReceived;
-            }
-
-            _socket?.Dispose();
-            _socket = null;
-        }
-
-        public void Dispose()
-        {
-            Stop();
-        }
-    }
-}

Frameworks/MQTTnet.UniversalWindows/MqttServerFactory.cs

@@ -1,15 +0,0 @@
-using System;
-using MQTTnet.Core.Server;
-
-namespace MQTTnet
-{
-    public class MqttServerFactory
-    {
-        public MqttServer CreateMqttServer(MqttServerOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            return new MqttServer(options, new MqttServerAdapter());
-        }
-    }
-}

Frameworks/MQTTnet.UniversalWindows/MqttTcpChannel.cs

@@ -1,62 +0,0 @@
-using System;
-using System.Runtime.InteropServices.WindowsRuntime;
-using System.Threading.Tasks;
-using Windows.Networking;
-using Windows.Networking.Sockets;
-using Windows.Storage.Streams;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using Buffer = Windows.Storage.Streams.Buffer;
-
-namespace MQTTnet
-{
-    public sealed class MqttTcpChannel : IMqttCommunicationChannel, IDisposable
-    {
-        private readonly StreamSocket _socket;
-
-        public MqttTcpChannel()
-        {
-            _socket = new StreamSocket();
-        }
-
-        public MqttTcpChannel(StreamSocket socket)
-        {
-            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
-        }
-
-        public async Task ConnectAsync(MqttClientOptions options)
-        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
-
-            await _socket.ConnectAsync(new HostName(options.Server), options.Port.ToString());
-        }
-
-        public async Task DisconnectAsync()
-        {
-            await _socket.CancelIOAsync();
-            _socket.Dispose();
-        }
-
-        public async Task WriteAsync(byte[] buffer)
-        {
-            if (buffer == null) throw new ArgumentNullException(nameof(buffer));
-
-            await _socket.OutputStream.WriteAsync(buffer.AsBuffer());
-            await _socket.OutputStream.FlushAsync();
-        }
-
-        public async Task ReadAsync(byte[] buffer)
-        {
-            var buffer2 = new Buffer((uint)buffer.Length);
-            await _socket.InputStream.ReadAsync(buffer2, (uint)buffer.Length, InputStreamOptions.None);
-
-            var array2 = buffer2.ToArray();
-            Array.Copy(array2, buffer, array2.Length);
-        }
-
-        public void Dispose()
-        {
-            _socket?.Dispose();
-        }
-    }
-}

Frameworks/MQTTnet.UniversalWindows/Properties/AssemblyInfo.cs

@@ -1,14 +0,0 @@
-using System.Reflection;
-using System.Runtime.InteropServices;
-
-[assembly: AssemblyTitle("MQTTnet")]
-[assembly: AssemblyDescription("MQTTnet for Universal Windows")]
-[assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("Christian Kratky")]
-[assembly: AssemblyProduct("MQTTnet")]
-[assembly: AssemblyCopyright("Copyright © Christian Kratky 2016-2017")]
-[assembly: AssemblyTrademark("")]
-[assembly: AssemblyCulture("")]
-[assembly: ComVisible(false)]
-[assembly: AssemblyVersion("2.1.1.0")]
-[assembly: AssemblyFileVersion("2.1.1.0")]

Frameworks/MQTTnet.UniversalWindows/Properties/MQTTnet.Universal.rd.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
-  <Library Name="MQTTnet.Universal">
-  </Library>
-</Directives>

Frameworks/MQTTnet.UniversalWindows/project.json

@@ -1,17 +0,0 @@
-{
-  "dependencies": {
-    "Microsoft.NETCore.UniversalWindowsPlatform": "5.1.0"
-  },
-  "frameworks": {
-    "uap10.0": {},
-    "netstandard1.1": {}
-  },
-  "runtimes": {
-    "win10-arm": {},
-    "win10-arm-aot": {},
-    "win10-x86": {},
-    "win10-x86-aot": {},
-    "win10-x64": {},
-    "win10-x64-aot": {}
-  }
-}

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017 Christian
+Copyright (c) 2017 Christian Kratky
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

MQTTnet.Core/Adapter/IMqttChannelAdapter.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.Packets;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Core.Adapter
+{
+    public interface IMqttChannelAdapter
+    {
+        IMqttPacketSerializer PacketSerializer { get; }
+
+        Task ConnectAsync(TimeSpan timeout);
+
+        Task DisconnectAsync(TimeSpan timeout);
+
+        Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, IEnumerable<MqttBasePacket> packets);
+
+        Task<MqttBasePacket> ReceivePacketAsync(TimeSpan timeout, CancellationToken cancellationToken);
+    }
+}

MQTTnet.Core/Adapter/IMqttCommunicationAdapter.cs

@@ -1,18 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Packets;
-
-namespace MQTTnet.Core.Adapter
-{
-    public interface IMqttCommunicationAdapter
-    {
-        Task ConnectAsync(MqttClientOptions options, TimeSpan timeout);
-
-        Task DisconnectAsync();
-
-        Task SendPacketAsync(MqttBasePacket packet, TimeSpan timeout);
-
-        Task<MqttBasePacket> ReceivePacketAsync(TimeSpan timeout);
-    }
-}

MQTTnet.Core/Adapter/IMqttServerAdapter.cs

@@ -1,14 +1,14 @@
 using System;
+using System.Threading.Tasks;
 using MQTTnet.Core.Server;
 
 namespace MQTTnet.Core.Adapter
 {
     public interface IMqttServerAdapter
     {
-        event EventHandler<MqttClientConnectedEventArgs> ClientConnected;
+        event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
 
-        void Start(MqttServerOptions options);
+        Task StartAsync(MqttServerOptions options);
-
+        Task StopAsync();
-        void Stop();
     }
 }

MQTTnet.Core/Adapter/MqttChannelAdapter.cs

@@ -0,0 +1,184 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.Channel;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Exceptions;
+using MQTTnet.Core.Internal;
+using MQTTnet.Core.Packets;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Core.Adapter
+{
+    public class MqttChannelAdapter : IMqttChannelAdapter
+    {
+        private const uint ErrorOperationAborted = 0x800703E3;
+
+        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 async Task ConnectAsync(TimeSpan timeout)
+        {
+            _logger.Info<MqttChannelAdapter>("Connecting [Timeout={0}]", timeout);
+
+            await ExecuteAndWrapExceptionAsync(() => _channel.ConnectAsync().TimeoutAfter(timeout));
+        }
+
+        public async Task DisconnectAsync(TimeSpan timeout)
+        {
+            _logger.Info<MqttChannelAdapter>("Disconnecting [Timeout={0}]", timeout);
+
+            await ExecuteAndWrapExceptionAsync(() => _channel.DisconnectAsync().TimeoutAfter(timeout));
+        }
+
+        public async Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, IEnumerable<MqttBasePacket> packets)
+        {
+            await ExecuteAndWrapExceptionAsync(async () =>
+            {
+                await _semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
+                try
+                {
+                    foreach (var packet in packets)
+                    {
+                        if (packet == null)
+                        {
+                            continue;
+                        }
+
+                        _logger.Trace<MqttChannelAdapter>("TX >>> {0} [Timeout={1}]", packet, timeout);
+
+                        var writeBuffer = PacketSerializer.Serialize(packet);
+                        await _channel.SendStream.WriteAsync(writeBuffer, 0, writeBuffer.Length, cancellationToken).ConfigureAwait(false);
+                    }
+
+                    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)
+        {
+            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);
+                    if (packet == null)
+                    {
+                        throw new MqttProtocolViolationException("Received malformed packet.");
+                    }
+
+                    _logger.Trace<MqttChannelAdapter>("RX <<< {0}", packet);
+                }
+                finally
+                {
+                    receivedMqttPacket?.Dispose();
+                }
+            });
+
+            return packet;
+        }
+
+        private static async Task<ReceivedMqttPacket> ReceiveAsync(Stream stream, CancellationToken cancellationToken)
+        {
+            var header = MqttPacketReader.ReadHeaderFromSource(stream, cancellationToken);
+            if (header == null)
+            {
+                return null;
+            }
+
+            if (header.BodyLength == 0)
+            {
+                return new ReceivedMqttPacket(header, new MemoryStream(0));
+            }
+
+            var body = new byte[header.BodyLength];
+
+            var offset = 0;
+            do
+            {
+                var readBytesCount = await stream.ReadAsync(body, offset, body.Length - offset, cancellationToken).ConfigureAwait(false);
+                offset += readBytesCount;
+            } while (offset < header.BodyLength);
+
+            return new ReceivedMqttPacket(header, new MemoryStream(body, 0, body.Length));
+        }
+
+        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 (Exception exception)
+            {
+                throw new MqttCommunicationException(exception);
+            }
+        }
+    }
+}

MQTTnet.Core/Adapter/MqttChannelAdapterExtensions.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.Packets;
+
+namespace MQTTnet.Core.Adapter
+{
+    public static class MqttChannelAdapterExtensions
+    {
+        public static Task SendPacketsAsync(this IMqttChannelAdapter adapter, TimeSpan timeout, CancellationToken cancellationToken, params MqttBasePacket[] packets)
+        {
+            if (adapter == null) throw new ArgumentNullException(nameof(adapter));
+
+            return adapter.SendPacketsAsync(timeout, cancellationToken, packets);
+        }
+    }
+}

MQTTnet.Core/Adapter/MqttChannelCommunicationAdapter.cs

@@ -1,88 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using MQTTnet.Core.Channel;
-using MQTTnet.Core.Client;
-using MQTTnet.Core.Diagnostics;
-using MQTTnet.Core.Exceptions;
-using MQTTnet.Core.Packets;
-using MQTTnet.Core.Serializer;
-
-namespace MQTTnet.Core.Adapter
-{
-    public class MqttChannelCommunicationAdapter : IMqttCommunicationAdapter
-    {
-        private readonly IMqttPacketSerializer _serializer;
-        private readonly IMqttCommunicationChannel _channel;
-
-        public MqttChannelCommunicationAdapter(IMqttCommunicationChannel channel, IMqttPacketSerializer serializer)
-        {
-            _channel = channel ?? throw new ArgumentNullException(nameof(channel));
-            _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
-        }
-
-        public async Task ConnectAsync(MqttClientOptions options, TimeSpan timeout)
-        {
-            var task = _channel.ConnectAsync(options);
-            if (await Task.WhenAny(Task.Delay(timeout), task) != task)
-            {
-                throw new MqttCommunicationTimedOutException();
-            }
-        }
-
-        public async Task DisconnectAsync()
-        {
-            await _channel.DisconnectAsync();
-        }
-
-        public async Task SendPacketAsync(MqttBasePacket packet, TimeSpan timeout)
-        {
-            MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), $"TX >>> {packet} [Timeout={timeout}]");
-
-            bool hasTimeout;
-            try
-            {
-                var task = _serializer.SerializeAsync(packet, _channel);
-                hasTimeout = await Task.WhenAny(Task.Delay(timeout), task) != task;
-            }
-            catch (Exception exception)
-            {
-                throw new MqttCommunicationException(exception);
-            }
-
-            if (hasTimeout)
-            {
-                throw new MqttCommunicationTimedOutException();
-            }
-        }
-
-        public async Task<MqttBasePacket> ReceivePacketAsync(TimeSpan timeout)
-        {
-            MqttBasePacket packet;
-            if (timeout > TimeSpan.Zero)
-            {
-                var workerTask = _serializer.DeserializeAsync(_channel);
-                var timeoutTask = Task.Delay(timeout);
-                var hasTimeout = Task.WhenAny(timeoutTask, workerTask) == timeoutTask;
-
-                if (hasTimeout)
-                {
-                    throw new MqttCommunicationTimedOutException();
-                }
-
-                packet = workerTask.Result;
-            }
-            else
-            {
-                packet = await _serializer.DeserializeAsync(_channel);
-            }
-
-            if (packet == null)
-            {
-                throw new MqttProtocolViolationException("Received malformed packet.");
-            }
-
-            MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), $"RX <<< {packet}");
-            return packet;
-        }
-    }
-}

MQTTnet.Core/Adapter/MqttClientConnectedEventArgs.cs

@@ -1,17 +0,0 @@
-using System;
-
-namespace MQTTnet.Core.Adapter
-{
-    public class MqttClientConnectedEventArgs : EventArgs
-    {
-        public MqttClientConnectedEventArgs(string identifier, IMqttCommunicationAdapter clientAdapter)
-        {
-            Identifier = identifier ?? throw new ArgumentNullException(nameof(identifier));
-            ClientAdapter = clientAdapter ?? throw new ArgumentNullException(nameof(clientAdapter));
-        }
-
-        public string Identifier { get; }
-
-        public IMqttCommunicationAdapter ClientAdapter { get; }
-    }
-}

MQTTnet.Core/Adapter/MqttConnectingFailedException.cs

@@ -5,7 +5,7 @@ namespace MQTTnet.Core.Adapter
 {
     public class MqttConnectingFailedException : MqttCommunicationException
     {
-        public MqttConnectingFailedException(MqttConnectReturnCode returnCode) 
+        public MqttConnectingFailedException(MqttConnectReturnCode returnCode)
             : base($"Connecting with MQTT server failed ({returnCode}).")
         {
             ReturnCode = returnCode;

MQTTnet.Core/Adapter/MqttServerAdapterClientAcceptedEventArgs.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core.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; }
+    }
+}

MQTTnet.Core/Adapter/ReceivedMqttPacket.cs

@@ -0,0 +1,24 @@
+using System;
+using System.IO;
+using MQTTnet.Core.Packets;
+
+namespace MQTTnet.Core.Adapter
+{
+    public sealed class ReceivedMqttPacket : IDisposable
+    {
+        public ReceivedMqttPacket(MqttPacketHeader header, MemoryStream body)
+        {
+            Header = header ?? throw new ArgumentNullException(nameof(header));
+            Body = body ?? throw new ArgumentNullException(nameof(body));
+        }
+
+        public MqttPacketHeader Header { get; }
+
+        public MemoryStream Body { get; }
+
+        public void Dispose()
+        {
+            Body?.Dispose();
+        }
+    }
+}

MQTTnet.Core/ApplicationMessagePublisherExtensions.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core
+{
+    public static class ApplicationMessagePublisherExtensions
+    {
+        public static Task PublishAsync(this IApplicationMessagePublisher client, params MqttApplicationMessage[] applicationMessages)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
+
+            return client.PublishAsync(applicationMessages);
+        }
+    }
+}

MQTTnet.Core/Channel/IMqttChannel.cs

@@ -0,0 +1,14 @@
+using System.Threading.Tasks;
+using System.IO;
+
+namespace MQTTnet.Core.Channel
+{
+    public interface IMqttChannel
+    {
+        Stream SendStream { get; }
+        Stream ReceiveStream { get; }
+
+        Task ConnectAsync();
+        Task DisconnectAsync();
+    }
+}

MQTTnet.Core/Channel/IMqttCommunicationChannel.cs

@@ -1,16 +0,0 @@
-using System.Threading.Tasks;
-using MQTTnet.Core.Client;
-
-namespace MQTTnet.Core.Channel
-{
-    public interface IMqttCommunicationChannel
-    {
-        Task ConnectAsync(MqttClientOptions options);
-
-        Task DisconnectAsync();
-
-        Task WriteAsync(byte[] buffer);
-
-        Task ReadAsync(byte[] buffer);
-    }
-}

MQTTnet.Core/Client/IMqttClient.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MQTTnet.Core.Packets;
+
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher
+    {
+        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> topicFilters);
+    }
+}

MQTTnet.Core/Client/IMqttClientAdapterFactory.cs

@@ -0,0 +1,10 @@
+using MQTTnet.Core.Adapter;
+using MQTTnet.Core.Diagnostics;
+
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClientAdapterFactory
+    {
+        IMqttChannelAdapter CreateClientAdapter(IMqttClientChannelOptions options, IMqttNetLogger logger);
+    }
+}

MQTTnet.Core/Client/IMqttClientChannelOptions.cs

@@ -0,0 +1,7 @@
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClientChannelOptions
+    {
+        MqttClientTlsOptions TlsOptions { get; }
+    }
+}

MQTTnet.Core/Client/IMqttClientCredentials.cs

@@ -0,0 +1,8 @@
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClientCredentials
+    {
+        string Password { get; }
+        string Username { get; }
+    }
+}

MQTTnet.Core/Client/IMqttClientFactory.cs

@@ -0,0 +1,16 @@
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.ManagedClient;
+
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClientFactory
+    {
+        IMqttClient CreateMqttClient();
+
+        IMqttClient CreateMqttClient(IMqttNetLogger logger);
+        
+        IManagedMqttClient CreateManagedMqttClient();
+
+        IManagedMqttClient CreateManagedMqttClient(IMqttNetLogger logger);
+    }
+}

MQTTnet.Core/Client/IMqttClientOptions.cs

@@ -0,0 +1,20 @@
+using System;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Core.Client
+{
+    public interface IMqttClientOptions
+    {
+        string ClientId { get; }
+
+        IMqttClientCredentials Credentials { get; }
+        bool CleanSession { get; }
+        MqttApplicationMessage WillMessage { get; }
+        
+        TimeSpan CommunicationTimeout { get; }
+        TimeSpan KeepAlivePeriod { get; }
+        MqttProtocolVersion ProtocolVersion { get; }
+
+        IMqttClientChannelOptions ChannelOptions { get; }
+    }
+}

MQTTnet.Core/Client/MqttClient.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
@@ -13,155 +12,195 @@ using MQTTnet.Core.Protocol;
 
 namespace MQTTnet.Core.Client
 {
-    public class MqttClient
+    public class MqttClient : IMqttClient
     {
-        private readonly ConcurrentDictionary<ushort, MqttPublishPacket> _pendingExactlyOncePublishPackets = new ConcurrentDictionary<ushort, MqttPublishPacket>();
+        private readonly HashSet<ushort> _unacknowledgedPublishPackets = new HashSet<ushort>();
-        private readonly HashSet<ushort> _processedPublishPackets = new HashSet<ushort>();
 
-        private readonly MqttPacketDispatcher _packetDispatcher = new MqttPacketDispatcher();
+        private readonly IMqttClientAdapterFactory _adapterFactory;
-        private readonly MqttClientOptions _options;
+        private readonly MqttPacketDispatcher _packetDispatcher;
-        private readonly IMqttCommunicationAdapter _adapter;
+        private readonly IMqttNetLogger _logger;
 
+        private IMqttClientOptions _options;
+        private bool _isReceivingPackets;
         private int _latestPacketIdentifier;
         private CancellationTokenSource _cancellationTokenSource;
+        private IMqttChannelAdapter _adapter;
 
-        public MqttClient(MqttClientOptions options, IMqttCommunicationAdapter adapter)
+        public MqttClient(IMqttClientAdapterFactory channelFactory, IMqttNetLogger logger)
         {
-            _options = options ?? throw new ArgumentNullException(nameof(options));
+            _adapterFactory = channelFactory ?? throw new ArgumentNullException(nameof(channelFactory));
-            _adapter = adapter ?? throw new ArgumentNullException(nameof(adapter));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            
+            _packetDispatcher = new MqttPacketDispatcher(logger);
         }
 
-        public event EventHandler Connected;
+        public event EventHandler<MqttClientConnectedEventArgs> Connected;
-
+        public event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
-        public event EventHandler Disconnected;
-
         public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
 
         public bool IsConnected { get; private set; }
 
-        public async Task ConnectAsync(MqttApplicationMessage willApplicationMessage = null)
+        public async Task<MqttClientConnectResult> ConnectAsync(IMqttClientOptions options)
         {
-            MqttTrace.Verbose(nameof(MqttClient), "Trying to connect.");
+            if (options == null) throw new ArgumentNullException(nameof(options));
+            if (options.ChannelOptions == null) throw new ArgumentException("ChannelOptions are not set.");
 
-            if (IsConnected)
+            ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");
+
+            try
             {
-                throw new MqttProtocolViolationException("It is not allowed to connect with a server after the connection is established.");
+                _options = options;
+                _cancellationTokenSource = new CancellationTokenSource();
+                _latestPacketIdentifier = 0;
+                _packetDispatcher.Reset();
+
+                _adapter = _adapterFactory.CreateClientAdapter(options.ChannelOptions, _logger);
+                
+                _logger.Trace<MqttClient>("Trying to connect with server.");
+                await _adapter.ConnectAsync(_options.CommunicationTimeout).ConfigureAwait(false);
+                _logger.Trace<MqttClient>("Connection with server established.");
+
+                await StartReceivingPacketsAsync(_cancellationTokenSource.Token).ConfigureAwait(false);
+                var connectResponse = await AuthenticateAsync(options.WillMessage).ConfigureAwait(false);
+
+                _logger.Trace<MqttClient>("MQTT connection with server established.");
+
+                if (_options.KeepAlivePeriod != TimeSpan.Zero)
+                {
+                    StartSendingKeepAliveMessages(_cancellationTokenSource.Token);
+                }
+
+                IsConnected = true;
+                Connected?.Invoke(this, new MqttClientConnectedEventArgs(connectResponse.IsSessionPresent));
+                return new MqttClientConnectResult(connectResponse.IsSessionPresent);
             }
-
+            catch (Exception exception)
-            var connectPacket = new MqttConnectPacket
             {
-                ClientId = _options.ClientId,
+                _logger.Error<MqttClient>(exception, "Error while connecting with server.");
-                Username = _options.UserName,
+                await DisconnectInternalAsync().ConfigureAwait(false);
-                Password = _options.Password,
+                throw;
-                CleanSession = _options.CleanSession,
-                KeepAlivePeriod = (ushort)_options.KeepAlivePeriod.TotalSeconds,
-                WillMessage = willApplicationMessage
-            };
-
-            await _adapter.ConnectAsync(_options, _options.DefaultCommunicationTimeout);
-            MqttTrace.Verbose(nameof(MqttClient), "Connection with server established.");
-
-            _cancellationTokenSource = new CancellationTokenSource();
-            _latestPacketIdentifier = 0;
-            _processedPublishPackets.Clear();
-            _packetDispatcher.Reset();
-            IsConnected = true;
-
-            Task.Run(() => ReceivePackets(_cancellationTokenSource.Token), _cancellationTokenSource.Token).Forget();
-
-            var response = await SendAndReceiveAsync<MqttConnAckPacket>(connectPacket);
-            if (response.ConnectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
-            {
-                throw new MqttConnectingFailedException(response.ConnectReturnCode);
             }
-
-            if (_options.KeepAlivePeriod != TimeSpan.Zero)
-            {
-                Task.Run(() => SendKeepAliveMessagesAsync(_cancellationTokenSource.Token), _cancellationTokenSource.Token).Forget();
-            }
-
-            Connected?.Invoke(this, EventArgs.Empty);
         }
 
         public async Task DisconnectAsync()
         {
-            await SendAsync(new MqttDisconnectPacket());
+            if (!IsConnected)
-            await DisconnectInternalAsync();
+            {
+                return;
+            }
+
+            try
+            {
+                await SendAsync(new MqttDisconnectPacket()).ConfigureAwait(false);
+            }
+            finally
+            {
+                await DisconnectInternalAsync().ConfigureAwait(false);
+            }
         }
 
-        public Task<IList<MqttSubscribeResult>> SubscribeAsync(params TopicFilter[] topicFilters)
+        public async Task<IList<MqttSubscribeResult>> SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
         {
             if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
 
-            return SubscribeAsync(topicFilters.ToList());
-        }
-
-        public async Task<IList<MqttSubscribeResult>> SubscribeAsync(IList<TopicFilter> topicFilters)
-        {
-            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
-            if (!topicFilters.Any()) throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.8.3-3].");
             ThrowIfNotConnected();
 
             var subscribePacket = new MqttSubscribePacket
             {
                 PacketIdentifier = GetNewPacketIdentifier(),
-                TopicFilters = topicFilters
+                TopicFilters = topicFilters.ToList()
             };
 
-            var response = await SendAndReceiveAsync<MqttSubAckPacket>(subscribePacket);
+            var response = await SendAndReceiveAsync<MqttSubAckPacket>(subscribePacket).ConfigureAwait(false);
 
-            if (response.SubscribeReturnCodes.Count != topicFilters.Count)
+            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 topicFilters.Select((t, i) => new MqttSubscribeResult(t, response.SubscribeReturnCodes[i])).ToList();
+            return subscribePacket.TopicFilters.Select((t, i) => new MqttSubscribeResult(t, response.SubscribeReturnCodes[i])).ToList();
         }
 
-        public Task Unsubscribe(params string[] topicFilters)
+        public async Task UnsubscribeAsync(IEnumerable<string> topicFilters)
         {
             if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
 
-            return Unsubscribe(topicFilters.ToList());
-        }
-
-        public async Task Unsubscribe(IList<string> topicFilters)
-        {
-            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
-            if (!topicFilters.Any()) throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.10.3-2].");
             ThrowIfNotConnected();
 
             var unsubscribePacket = new MqttUnsubscribePacket
             {
                 PacketIdentifier = GetNewPacketIdentifier(),
-                TopicFilters = topicFilters
+                TopicFilters = topicFilters.ToList()
             };
 
             await SendAndReceiveAsync<MqttUnsubAckPacket>(unsubscribePacket);
         }
 
-        public async Task PublishAsync(MqttApplicationMessage applicationMessage)
+        public async Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages)
         {
-            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
             ThrowIfNotConnected();
 
-            var publishPacket = applicationMessage.ToPublishPacket();
+            var publishPackets = applicationMessages.Select(m => m.ToPublishPacket());
 
-            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
+            foreach (var qosGroup in publishPackets.GroupBy(p => p.QualityOfServiceLevel))
             {
-                await SendAsync(publishPacket);
+                var qosPackets = qosGroup.ToArray();
+                switch (qosGroup.Key)
+                {
+                    case MqttQualityOfServiceLevel.AtMostOnce:
+                        {
+                            // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
+                            await _adapter.SendPacketsAsync(_options.CommunicationTimeout, _cancellationTokenSource.Token, qosPackets).ConfigureAwait(false);
+                            break;
+                        }
+                    case MqttQualityOfServiceLevel.AtLeastOnce:
+                        {
+                            foreach (var publishPacket in qosPackets)
+                            {
+                                publishPacket.PacketIdentifier = GetNewPacketIdentifier();
+                                await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket).ConfigureAwait(false);
+                            }
+
+                            break;
+                        }
+                    case MqttQualityOfServiceLevel.ExactlyOnce:
+                        {
+                            foreach (var publishPacket in qosPackets)
+                            {
+                                publishPacket.PacketIdentifier = GetNewPacketIdentifier();
+                                var pubRecPacket = await SendAndReceiveAsync<MqttPubRecPacket>(publishPacket).ConfigureAwait(false);
+                                await SendAndReceiveAsync<MqttPubCompPacket>(pubRecPacket.CreateResponse<MqttPubRelPacket>()).ConfigureAwait(false);
+                            }
+
+                            break;
+                        }
+                    default:
+                        {
+                            throw new InvalidOperationException();
+                        }
+                }
             }
-            else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+        }
+
+        private async Task<MqttConnAckPacket> AuthenticateAsync(MqttApplicationMessage willApplicationMessage)
+        {
+            var connectPacket = new MqttConnectPacket
             {
-                publishPacket.PacketIdentifier = GetNewPacketIdentifier();
+                ClientId = _options.ClientId,
-                await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket);
+                Username = _options.Credentials?.Username,
-            }
+                Password = _options.Credentials?.Password,
-            else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+                CleanSession = _options.CleanSession,
+                KeepAlivePeriod = (ushort)_options.KeepAlivePeriod.TotalSeconds,
+                WillMessage = willApplicationMessage
+            };
+
+            var response = await SendAndReceiveAsync<MqttConnAckPacket>(connectPacket).ConfigureAwait(false);
+            if (response.ConnectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
             {
-                publishPacket.PacketIdentifier = GetNewPacketIdentifier();
+                throw new MqttConnectingFailedException(response.ConnectReturnCode);
-                await SendAndReceiveAsync<MqttPubRecPacket>(publishPacket);
-                await SendAsync(publishPacket.CreateResponse<MqttPubCompPacket>());
             }
+
+            return response;
         }
 
         private void ThrowIfNotConnected()
@@ -169,76 +208,91 @@ namespace MQTTnet.Core.Client
             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()
         {
+            var clientWasConnected = IsConnected;
+            IsConnected = false;
+
+            var cts = _cancellationTokenSource;
+            if (cts == null || cts.IsCancellationRequested)
+            {
+                return;
+            }
+
+            cts.Cancel(false);
+            cts.Dispose();
+            _cancellationTokenSource = null;
+
             try
             {
-                await _adapter.DisconnectAsync();
+                await _adapter.DisconnectAsync(_options.CommunicationTimeout).ConfigureAwait(false);
+                _logger.Info<MqttClient>("Disconnected from adapter.");
             }
-            catch
+            catch (Exception exception)
             {
+                _logger.Warning<MqttClient>(exception, "Error while disconnecting from adapter.");
             }
             finally
             {
-                _cancellationTokenSource?.Cancel();
+                _logger.Info<MqttClient>("Disconnected.");
-                IsConnected = false;
+                Disconnected?.Invoke(this, new MqttClientDisconnectedEventArgs(clientWasConnected));
-                Disconnected?.Invoke(this, EventArgs.Empty);
             }
         }
 
-        private async void ProcessReceivedPacket(MqttBasePacket mqttPacket)
+        private async Task ProcessReceivedPacketAsync(MqttBasePacket packet)
         {
             try
             {
-                if (mqttPacket is MqttPingReqPacket)
+                _logger.Info<MqttClient>("Received <<< {0}", packet);
+
+                if (packet is MqttPingReqPacket)
                 {
                     await SendAsync(new MqttPingRespPacket());
                     return;
                 }
 
-                if (mqttPacket is MqttDisconnectPacket)
+                if (packet is MqttDisconnectPacket)
                 {
                     await DisconnectAsync();
                     return;
                 }
 
-                var publishPacket = mqttPacket as MqttPublishPacket;
+                if (packet is MqttPublishPacket publishPacket)
-                if (publishPacket != null)
                 {
                     await ProcessReceivedPublishPacket(publishPacket);
                     return;
                 }
 
-                var pubRelPacket = mqttPacket as MqttPubRelPacket;
+                if (packet is MqttPubRelPacket pubRelPacket)
-                if (pubRelPacket != null)
                 {
                     await ProcessReceivedPubRelPacket(pubRelPacket);
                     return;
                 }
 
-                _packetDispatcher.Dispatch(mqttPacket);
+                _packetDispatcher.Dispatch(packet);
             }
             catch (Exception exception)
             {
-                MqttTrace.Error(nameof(MqttClient), exception, "Error while processing received packet.");
+                _logger.Error<MqttClient>(exception, "Unhandled exception while processing received packet.");
             }
         }
 
         private void FireApplicationMessageReceivedEvent(MqttPublishPacket publishPacket)
         {
-            if (publishPacket.QualityOfServiceLevel != MqttQualityOfServiceLevel.AtMostOnce)
+            try
             {
-                _processedPublishPackets.Add(publishPacket.PacketIdentifier);
+                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.");
             }
-
-            var applicationMessage = new MqttApplicationMessage(
-                publishPacket.Topic,
-                publishPacket.Payload,
-                publishPacket.QualityOfServiceLevel,
-                publishPacket.Retain
-            );
-
-            ApplicationMessageReceived?.Invoke(this, new MqttApplicationMessageReceivedEventArgs(applicationMessage));
         }
 
         private async Task ProcessReceivedPublishPacket(MqttPublishPacket publishPacket)
@@ -246,66 +300,52 @@ namespace MQTTnet.Core.Client
             if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
             {
                 FireApplicationMessageReceivedEvent(publishPacket);
+                return;
             }
-            else
+
+            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
             {
-                if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+                FireApplicationMessageReceivedEvent(publishPacket);
-                {
+                await SendAsync(new MqttPubAckPacket { PacketIdentifier = publishPacket.PacketIdentifier });
-                    FireApplicationMessageReceivedEvent(publishPacket);
+                return;
-                    await SendAsync(new MqttPubAckPacket { PacketIdentifier = publishPacket.PacketIdentifier });
-                }
-                else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
-                {
-                    _pendingExactlyOncePublishPackets[publishPacket.PacketIdentifier] = publishPacket;
-                    await SendAsync(new MqttPubRecPacket { PacketIdentifier = publishPacket.PacketIdentifier });
-                }
             }
+
+            if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+            {
+                // QoS 2 is implement as method "B" [4.3.3 QoS 2: Exactly once delivery]
+                lock (_unacknowledgedPublishPackets)
+                {
+                    _unacknowledgedPublishPackets.Add(publishPacket.PacketIdentifier);
+                }
+
+                FireApplicationMessageReceivedEvent(publishPacket);
+                await SendAsync(new MqttPubRecPacket { PacketIdentifier = publishPacket.PacketIdentifier });
+                return;
+            }
+
+            throw new MqttCommunicationException("Received a not supported QoS level.");
         }
 
-        private async Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket)
+        private Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket)
         {
-            MqttPublishPacket originalPublishPacket;
+            lock (_unacknowledgedPublishPackets)
-            if (!_pendingExactlyOncePublishPackets.TryRemove(pubRelPacket.PacketIdentifier, out originalPublishPacket))
             {
-                throw new MqttCommunicationException();
+                _unacknowledgedPublishPackets.Remove(pubRelPacket.PacketIdentifier);
             }
 
-            await SendAsync(originalPublishPacket.CreateResponse<MqttPubCompPacket>());
+            return SendAsync(pubRelPacket.CreateResponse<MqttPubCompPacket>());
-
-            FireApplicationMessageReceivedEvent(originalPublishPacket);
         }
 
         private Task SendAsync(MqttBasePacket packet)
         {
-            return _adapter.SendPacketAsync(packet, _options.DefaultCommunicationTimeout);
+            return _adapter.SendPacketsAsync(_options.CommunicationTimeout, _cancellationTokenSource.Token, packet);
         }
 
         private async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket) where TResponsePacket : MqttBasePacket
         {
-            bool ResponsePacketSelector(MqttBasePacket p)
+            var packetAwaiter = _packetDispatcher.WaitForPacketAsync(requestPacket, typeof(TResponsePacket), _options.CommunicationTimeout);
-            {
+            await _adapter.SendPacketsAsync(_options.CommunicationTimeout, _cancellationTokenSource.Token, requestPacket).ConfigureAwait(false);
-                var p1 = p as TResponsePacket;
+            return (TResponsePacket)await packetAwaiter.ConfigureAwait(false);
-                if (p1 == null)
-                {
-                    return false;
-                }
-
-                var pi1 = requestPacket as IPacketWithIdentifier;
-                var pi2 = p as IPacketWithIdentifier;
-
-                if (pi1 != null && pi2 != null)
-                {
-                    if (pi1.PacketIdentifier != pi2.PacketIdentifier)
-                    {
-                        return false;
-                    }
-                }
-
-                return true;
-            }
-
-            await _adapter.SendPacketAsync(requestPacket, _options.DefaultCommunicationTimeout);
-            return (TResponsePacket)await _packetDispatcher.WaitForPacketAsync(ResponsePacketSelector, _options.DefaultCommunicationTimeout);
         }
 
         private ushort GetNewPacketIdentifier()
@@ -315,57 +355,133 @@ namespace MQTTnet.Core.Client
 
         private async Task SendKeepAliveMessagesAsync(CancellationToken cancellationToken)
         {
-            MqttTrace.Information(nameof(MqttClient), "Start sending keep alive packets.");
+            _logger.Info<MqttClient>("Start sending keep alive packets.");
 
             try
             {
                 while (!cancellationToken.IsCancellationRequested)
                 {
-                    await Task.Delay(_options.KeepAlivePeriod, cancellationToken);
+                    await Task.Delay(_options.KeepAlivePeriod, cancellationToken).ConfigureAwait(false);
-                    await SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket());
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        return;
+                    }
+
+                    await SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket()).ConfigureAwait(false);
                 }
             }
+            catch (OperationCanceledException)
+            {
+                if (cancellationToken.IsCancellationRequested)
+                {
+                    return;
+                }
+
+                await DisconnectInternalAsync().ConfigureAwait(false);
+            }
             catch (MqttCommunicationException exception)
             {
-                MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
+                if (cancellationToken.IsCancellationRequested)
+                {
+                    return;
+                }
+
+                _logger.Warning<MqttClient>(exception, "MQTT communication exception while sending/receiving keep alive packets.");
+                await DisconnectInternalAsync().ConfigureAwait(false);
             }
             catch (Exception exception)
             {
-                MqttTrace.Warning(nameof(MqttClient), exception, "Error while sending/receiving keep alive packets.");
+                _logger.Warning<MqttClient>(exception, "Unhandled exception while sending/receiving keep alive packets.");
+                await DisconnectInternalAsync().ConfigureAwait(false);
             }
             finally
             {
-                MqttTrace.Information(nameof(MqttClient), "Stopped sending keep alive packets.");
+                _logger.Info<MqttClient>("Stopped sending keep alive packets.");
-                await DisconnectInternalAsync();
             }
         }
 
-        private async Task ReceivePackets(CancellationToken cancellationToken)
+        private async Task ReceivePacketsAsync(CancellationToken cancellationToken)
         {
-            MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
+            _logger.Info<MqttClient>("Start receiving packets.");
+
             try
             {
                 while (!cancellationToken.IsCancellationRequested)
                 {
-                    var mqttPacket = await _adapter.ReceivePacketAsync(TimeSpan.Zero);
+                    _isReceivingPackets = true;
-                    MqttTrace.Information(nameof(MqttClient), $"Received <<< {mqttPacket}");
 
-                    Task.Run(() => ProcessReceivedPacket(mqttPacket), cancellationToken).Forget();
+                    var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
+
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        return;
+                    }
+
+                    StartProcessReceivedPacket(packet, cancellationToken);
                 }
             }
+            catch (OperationCanceledException)
+            {
+                if (cancellationToken.IsCancellationRequested)
+                {
+                    return;
+                }
+
+                await DisconnectInternalAsync().ConfigureAwait(false);
+            }
             catch (MqttCommunicationException exception)
             {
-                MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
+                if (cancellationToken.IsCancellationRequested)
+                {
+                    return;
+                }
+
+                _logger.Warning<MqttClient>(exception, "MQTT communication exception while receiving packets.");
+                await DisconnectInternalAsync().ConfigureAwait(false);
             }
             catch (Exception exception)
             {
-                MqttTrace.Error(nameof(MqttClient), exception, "Error while receiving packets.");
+                _logger.Error<MqttClient>(exception, "Unhandled exception while receiving packets.");
+                await DisconnectInternalAsync().ConfigureAwait(false);
             }
             finally
             {
-                MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
+                _logger.Info<MqttClient>("Stopped receiving packets.");
-                await DisconnectInternalAsync();
             }
         }
+
+        private void StartProcessReceivedPacket(MqttBasePacket packet, CancellationToken cancellationToken)
+        {
+#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+            Task.Run(
+                () => ProcessReceivedPacketAsync(packet),
+                cancellationToken).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+        }
+
+        private async Task StartReceivingPacketsAsync(CancellationToken cancellationToken)
+        {
+            _isReceivingPackets = false;
+
+#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 ReceivePacketsAsync(cancellationToken),
+                cancellationToken).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+
+            while (!_isReceivingPackets && !cancellationToken.IsCancellationRequested)
+            {
+                await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken).ConfigureAwait(false);
+            }
+        }
+
+        private void StartSendingKeepAliveMessages(CancellationToken cancellationToken)
+        {
+#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 SendKeepAliveMessagesAsync(cancellationToken), 
+                cancellationToken).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+        }
     }
 }

MQTTnet.Core/Client/MqttClientConnectResult.cs

@@ -0,0 +1,12 @@
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientConnectResult
+    {
+        public MqttClientConnectResult(bool isSessionPresent)
+        {
+            IsSessionPresent = isSessionPresent;
+        }
+
+        public bool IsSessionPresent { get; }
+    }
+}

MQTTnet.Core/Client/MqttClientConnectedEventArgs.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientConnectedEventArgs : EventArgs
+    {
+        public MqttClientConnectedEventArgs(bool isSessionPresent)
+        {
+            IsSessionPresent = isSessionPresent;
+        }
+
+        public bool IsSessionPresent { get; }
+    }
+}

MQTTnet.Core/Client/MqttClientCredentials.cs

@@ -0,0 +1,9 @@
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientCredentials : IMqttClientCredentials
+    {
+        public string Username { get; set; }
+
+        public string Password { get; set; }
+    }
+}

MQTTnet.Core/Client/MqttClientDisconnectedEventArgs.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientDisconnectedEventArgs : EventArgs
+    {
+        public MqttClientDisconnectedEventArgs(bool clientWasConnected)
+        {
+            ClientWasConnected = clientWasConnected;
+        }
+
+        public bool ClientWasConnected { get; }
+    }
+}

MQTTnet.Core/Client/MqttClientExtensions.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core.Client
+{
+    public static class MqttClientExtensions
+    {
+        public static Task<IList<MqttSubscribeResult>> SubscribeAsync(this IMqttClient client, params TopicFilter[] topicFilters)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            return client.SubscribeAsync(topicFilters.ToList());
+        }
+
+        public static Task UnsubscribeAsync(this IMqttClient client, params string[] topicFilters)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            return client.UnsubscribeAsync(topicFilters.ToList());
+        }
+    }
+}

MQTTnet.Core/Client/MqttClientOptions.cs

@@ -1,23 +1,24 @@
 using System;
+using MQTTnet.Core.Serializer;
 
 namespace MQTTnet.Core.Client
 {
-    public class MqttClientOptions
+    public class MqttClientOptions : IMqttClientOptions
     {
-        public string Server { get; set; }
+        public MqttApplicationMessage WillMessage { get; set; }
 
-        public int Port { get; set; } = 1883;
+        public string ClientId { get; set; } = Guid.NewGuid().ToString("N");
-
-        public string UserName { get; set; }
-
-        public string Password { get; set; }
-
-        public string ClientId { get; set; } = Guid.NewGuid().ToString().Replace("-", string.Empty);
 
         public bool CleanSession { get; set; } = true;
 
+        public IMqttClientCredentials Credentials { get; set; } = new MqttClientCredentials();
+
         public TimeSpan KeepAlivePeriod { get; set; } = TimeSpan.FromSeconds(5);
 
-        public TimeSpan DefaultCommunicationTimeout { get; set; } = TimeSpan.FromSeconds(10);
+        public TimeSpan CommunicationTimeout { get; set; } = TimeSpan.FromSeconds(10);
+
+        public MqttProtocolVersion ProtocolVersion { get; set; } = MqttProtocolVersion.V311;
+
+        public IMqttClientChannelOptions ChannelOptions { get; set; }
     }
 }

MQTTnet.Core/Client/MqttClientOptionsBuilder.cs

@@ -0,0 +1,135 @@
+using System;
+using System.Linq;
+using MQTTnet.Core.Serializer;
+
+namespace MQTTnet.Core.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)
+                {
+                    _options.ChannelOptions = _tcpOptions;
+                }
+                else
+                {
+                    _options.ChannelOptions = _webSocketOptions;
+                }
+            }
+
+            _options.ChannelOptions = (IMqttClientChannelOptions)_tcpOptions ?? _webSocketOptions;
+
+            return _options;
+        }
+    }
+}

MQTTnet.Core/Client/MqttClientTcpOptions.cs

@@ -0,0 +1,11 @@
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientTcpOptions : IMqttClientChannelOptions
+    {
+        public string Server { get; set; }
+
+        public int? Port { get; set; }
+
+        public MqttClientTlsOptions TlsOptions { get; set; } = new MqttClientTlsOptions();
+    }
+}

MQTTnet.Core/Client/MqttClientTcpOptionsExtensions.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace MQTTnet.Core.Client
+{
+    public static class MqttClientTcpOptionsExtensions
+    {
+        public static int GetPort(this MqttClientTcpOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            if (options.Port.HasValue)
+            {
+                return options.Port.Value;
+            }
+
+            return !options.TlsOptions.UseTls ? 1883 : 8883;
+        }
+    }
+}

MQTTnet.Core/Client/MqttClientTlsOptions.cs

@@ -0,0 +1,17 @@
+using System.Collections.Generic;
+
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientTlsOptions
+    {
+        public bool UseTls { get; set; }
+
+        public bool IgnoreCertificateRevocationErrors { get; set; }
+
+        public bool IgnoreCertificateChainErrors { get; set; }
+
+        public bool AllowUntrustedCertificates { get; set; }
+
+        public List<byte[]> Certificates { get; set; }
+    }
+}

MQTTnet.Core/Client/MqttClientWebSocketOptions.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Net;
+
+namespace MQTTnet.Core.Client
+{
+    public class MqttClientWebSocketOptions : IMqttClientChannelOptions
+    {
+        public string Uri { get; set; }
+
+        public IDictionary<string, string> RequestHeaders { get; set; }
+
+        public ICollection<string> SubProtocols { get; set; }
+
+        public CookieContainer CookieContainer { get; set; }
+
+        public MqttClientTlsOptions TlsOptions { get; set; } = new MqttClientTlsOptions();
+    }
+}

MQTTnet.Core/Client/MqttPacketAwaiter.cs

@@ -1,16 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using MQTTnet.Core.Packets;
-
-namespace MQTTnet.Core.Client
-{
-    public class MqttPacketAwaiter : TaskCompletionSource<MqttBasePacket>
-    {
-        public MqttPacketAwaiter(Func<MqttBasePacket, bool> packetSelector)
-        {
-            PacketSelector = packetSelector ?? throw new ArgumentNullException(nameof(packetSelector));
-        }
-
-        public Func<MqttBasePacket, bool> PacketSelector { get; }
-    }
-}

MQTTnet.Core/Client/MqttPacketDispatcher.cs

@@ -1,111 +1,102 @@
 using System;
-using System.Collections.Generic;
+using System.Collections.Concurrent;
 using System.Threading.Tasks;
 using MQTTnet.Core.Diagnostics;
 using MQTTnet.Core.Exceptions;
+using MQTTnet.Core.Internal;
 using MQTTnet.Core.Packets;
 
 namespace MQTTnet.Core.Client
 {
     public class MqttPacketDispatcher
     {
-        private readonly object _syncRoot = new object();
+        private readonly ConcurrentDictionary<Type, TaskCompletionSource<MqttBasePacket>> _packetByResponseType = new ConcurrentDictionary<Type, TaskCompletionSource<MqttBasePacket>>();
-        private readonly List<MqttBasePacket> _receivedPackets = new List<MqttBasePacket>();
+        private readonly ConcurrentDictionary<Type, ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>> _packetByResponseTypeAndIdentifier = new ConcurrentDictionary<Type, ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>>();
-        private readonly List<MqttPacketAwaiter> _packetAwaiters = new List<MqttPacketAwaiter>();
+        private readonly IMqttNetLogger _logger;
 
-        public async Task<MqttBasePacket> WaitForPacketAsync(Func<MqttBasePacket, bool> selector, TimeSpan timeout)
+        public MqttPacketDispatcher(IMqttNetLogger logger)
         {
-            if (selector == null) throw new ArgumentNullException(nameof(selector));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
 
-            var packetAwaiter = AddPacketAwaiter(selector);
+        public async Task<MqttBasePacket> WaitForPacketAsync(MqttBasePacket request, Type responseType, TimeSpan timeout)
-            DispatchPendingPackets();
+        {
+            if (request == null) throw new ArgumentNullException(nameof(request));
 
-            var hasTimeout = await Task.WhenAny(Task.Delay(timeout), packetAwaiter.Task) != packetAwaiter.Task;
+            var packetAwaiter = AddPacketAwaiter(request, responseType);
-            RemovePacketAwaiter(packetAwaiter);
+            try
-
-            if (hasTimeout)
             {
-                MqttTrace.Warning(nameof(MqttPacketDispatcher), "Timeout while waiting for packet.");
+                return await packetAwaiter.Task.TimeoutAfter(timeout).ConfigureAwait(false);
-                throw new MqttCommunicationTimedOutException();
+            }
+            catch (MqttCommunicationTimedOutException)
+            {
+                _logger.Warning<MqttPacketDispatcher>("Timeout while waiting for packet of type '{0}'.", responseType.Name);
+                throw;
+            }
+            finally
+            {
+                RemovePacketAwaiter(request, responseType);
             }
-
-            return packetAwaiter.Task.Result;
         }
 
         public void Dispatch(MqttBasePacket packet)
         {
             if (packet == null) throw new ArgumentNullException(nameof(packet));
 
-            var packetDispatched = false;
+            var type = packet.GetType();
-            foreach (var packetAwaiter in GetPacketAwaiters())
+            if (packet is IMqttPacketWithIdentifier withIdentifier)
             {
-                if (packetAwaiter.PacketSelector(packet))
+                if (_packetByResponseTypeAndIdentifier.TryGetValue(type, out var byid))
                 {
-                    packetAwaiter.SetResult(packet);
+                    if (byid.TryRemove(withIdentifier.PacketIdentifier, out var tcs))
-                    packetDispatched = true;
+                    {
-                    break;
+                        tcs.TrySetResult(packet);
+                        return;
+                    }
                 }
             }
+            else if (_packetByResponseType.TryRemove(type, out var tcs))
+            {
+                tcs.TrySetResult(packet);
+                return;
+            }
 
-            lock (_syncRoot)
+            throw new InvalidOperationException($"Packet of type '{type.Name}' not handled or dispatched.");
-            {
-                if (!packetDispatched)
-                {
-                    _receivedPackets.Add(packet);
-                }
-                else
-                {
-                    _receivedPackets.Remove(packet);
-                }
-            }
         }
 
         public void Reset()
         {
-            lock (_syncRoot)
+            _packetByResponseTypeAndIdentifier.Clear();
-            {
+            _packetByResponseType.Clear();
-                _packetAwaiters.Clear();
-                _receivedPackets.Clear();
-            }
         }
 
-        private List<MqttPacketAwaiter> GetPacketAwaiters()
+        private TaskCompletionSource<MqttBasePacket> AddPacketAwaiter(MqttBasePacket request, Type responseType)
         {
-            lock (_packetAwaiters)
+            var tcs = new TaskCompletionSource<MqttBasePacket>();
+
+            if (request is IMqttPacketWithIdentifier requestWithIdentifier)
             {
-                return new List<MqttPacketAwaiter>(_packetAwaiters);
+                var byId = _packetByResponseTypeAndIdentifier.GetOrAdd(responseType, key => new ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>());
+                byId[requestWithIdentifier.PacketIdentifier] = tcs;
             }
+            else
+            {
+                _packetByResponseType[responseType] = tcs;
+            }
+
+            return tcs;
         }
 
-        private MqttPacketAwaiter AddPacketAwaiter(Func<MqttBasePacket, bool> selector)
+        private void RemovePacketAwaiter(MqttBasePacket request, Type responseType)
         {
-            lock (_syncRoot)
+            if (request is IMqttPacketWithIdentifier requestWithIdentifier)
             {
-                var packetAwaiter = new MqttPacketAwaiter(selector);
+                var byId = _packetByResponseTypeAndIdentifier.GetOrAdd(responseType, key => new ConcurrentDictionary<ushort, TaskCompletionSource<MqttBasePacket>>());
-                _packetAwaiters.Add(packetAwaiter);
+                byId.TryRemove(requestWithIdentifier.PacketIdentifier, out var _);
-                return packetAwaiter;
             }
-        }
+            else
-
-        private void RemovePacketAwaiter(MqttPacketAwaiter packetAwaiter)
-        {
-            lock (_syncRoot)
             {
-                _packetAwaiters.Remove(packetAwaiter);
+                _packetByResponseType.TryRemove(responseType, out var _);
-            }
-        }
-
-        private void DispatchPendingPackets()
-        {
-            List<MqttBasePacket> receivedPackets;
-            lock (_syncRoot)
-            {
-                receivedPackets = new List<MqttBasePacket>(_receivedPackets);
-            }
-
-            foreach (var pendingPacket in receivedPackets)
-            {
-                Dispatch(pendingPacket);
             }
         }
     }

MQTTnet.Core/Diagnostics/IMqttNetLogger.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public interface IMqttNetLogger
+    {
+        event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
+
+        void Trace<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);
+    }
+}

MQTTnet.Core/Diagnostics/MqttNetGlobalLog.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public static class MqttNetGlobalLog
+    {
+        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));
+        }
+    }
+}

MQTTnet.Core/Diagnostics/MqttNetLogLevel.cs

@@ -1,10 +1,13 @@
 namespace MQTTnet.Core.Diagnostics
 {
-    public enum  MqttTraceLevel
+    public enum MqttNetLogLevel
     {
         Verbose,
-        Information,
+
+        Info,
+
         Warning,
+
         Error
     }
 }

MQTTnet.Core/Diagnostics/MqttNetLogMessage.cs

@@ -2,10 +2,12 @@
 
 namespace MQTTnet.Core.Diagnostics
 {
-    public class MqttTraceMessagePublishedEventArgs : EventArgs
+    public sealed class MqttNetLogMessage
     {
-        public MqttTraceMessagePublishedEventArgs(int threadId, string source, MqttTraceLevel level, string message, Exception exception)
+        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;
@@ -13,11 +15,15 @@ namespace MQTTnet.Core.Diagnostics
             Exception = exception;
         }
 
+        public string LogId { get; }
+
+        public DateTime Timestamp { get; }
+
         public int ThreadId { get; }
 
         public string Source { get; }
 
-        public MqttTraceLevel Level { get; }
+        public MqttNetLogLevel Level { get; }
 
         public string Message { get; }
 

MQTTnet.Core/Diagnostics/MqttNetLogMessagePublishedEventArgs.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public sealed class MqttNetLogMessagePublishedEventArgs : EventArgs
+    {
+        public MqttNetLogMessagePublishedEventArgs(MqttNetLogMessage logMessage)
+        {
+            TraceMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+        }
+
+        public MqttNetLogMessage TraceMessage { get; }
+    }
+}

MQTTnet.Core/Diagnostics/MqttNetLogger.cs

@@ -0,0 +1,74 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public class MqttNetLogger : IMqttNetLogger
+    {
+        private readonly string _logId;
+
+        public MqttNetLogger(string logId = null)
+        {
+            _logId = logId;
+        }
+        
+        public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
+
+        public void Trace<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 = MqttNetGlobalLog.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)
+            {
+                MqttNetGlobalLog.Publish(traceMessage);
+            }
+
+            if (hasLocalListeners)
+            {
+                LogMessagePublished?.Invoke(this, new MqttNetLogMessagePublishedEventArgs(traceMessage));
+            }
+        }
+    }
+}

MQTTnet.Core/Diagnostics/MqttTrace.cs

@@ -1,44 +0,0 @@
-using System;
-
-namespace MQTTnet.Core.Diagnostics
-{
-    public static class MqttTrace
-    {
-        public static event EventHandler<MqttTraceMessagePublishedEventArgs> TraceMessagePublished;
-
-        public static void Verbose(string source, string message)
-        {
-            Publish(source, MqttTraceLevel.Verbose, null, message);
-        }
-
-        public static void Information(string source, string message)
-        {
-            Publish(source, MqttTraceLevel.Information, null, message);
-        }
-
-        public static void Warning(string source, string message)
-        {
-            Publish(source, MqttTraceLevel.Warning, null, message);
-        }
-
-        public static void Warning(string source, Exception exception, string message)
-        {
-            Publish(source, MqttTraceLevel.Warning, exception, message);
-        }
-
-        public static void Error(string source, string message)
-        {
-            Publish(source, MqttTraceLevel.Error, null, message);
-        }
-
-        public static void Error(string source, Exception exception, string message)
-        {
-            Publish(source, MqttTraceLevel.Error, exception, message);
-        }
-
-        private static void Publish(string source, MqttTraceLevel traceLevel, Exception exception, string message)
-        {
-            TraceMessagePublished?.Invoke(null, new MqttTraceMessagePublishedEventArgs(Environment.CurrentManagedThreadId, source, traceLevel, message, exception));
-        }
-    }
-}

MQTTnet.Core/Exceptions/MqttCommunicationException.cs

@@ -4,7 +4,7 @@ namespace MQTTnet.Core.Exceptions
 {
     public class MqttCommunicationException : Exception
     {
-        public MqttCommunicationException()
+        protected MqttCommunicationException()
         {
         }
 

MQTTnet.Core/Exceptions/MqttCommunicationTimedOutException.cs

@@ -1,6 +1,6 @@
 namespace MQTTnet.Core.Exceptions
 {
-    public class MqttCommunicationTimedOutException : MqttCommunicationException
+    public sealed class MqttCommunicationTimedOutException : MqttCommunicationException
     {
     }
 }

MQTTnet.Core/Exceptions/MqttProtocolViolationException.cs

@@ -2,9 +2,9 @@
 
 namespace MQTTnet.Core.Exceptions
 {
-    public class MqttProtocolViolationException : Exception
+    public sealed class MqttProtocolViolationException : Exception
     {
-        public MqttProtocolViolationException(string message) 
+        public MqttProtocolViolationException(string message)
             : base(message)
         {
         }

MQTTnet.Core/IApplicationMessagePublisher.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core
+{
+    public interface IApplicationMessagePublisher
+    {
+        Task PublishAsync(IEnumerable<MqttApplicationMessage> applicationMessages);
+    }
+}

MQTTnet.Core/IApplicationMessageReceiver.cs

@@ -0,0 +1,10 @@
+using System;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Core
+{
+    public interface IApplicationMessageReceiver
+    {
+        event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
+    }
+}

MQTTnet.Core/Internal/AsyncAutoResetEvent.cs

@@ -1,32 +0,0 @@
-using System.Collections.Generic;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Core.Internal
-{
-    public class AsyncGate
-    {
-        private readonly Queue<TaskCompletionSource<bool>> _waitingTasks = new Queue<TaskCompletionSource<bool>>();
-
-        public Task WaitOneAsync()
-        {
-            var tcs = new TaskCompletionSource<bool>();
-            lock (_waitingTasks)
-            {
-                _waitingTasks.Enqueue(tcs);
-            }
-
-            return tcs.Task;
-        }
-
-        public void Set()
-        {
-            lock (_waitingTasks)
-            {
-                if (_waitingTasks.Count > 0)
-                {
-                    _waitingTasks.Dequeue().SetResult(true);
-                }
-            }
-        }
-    }
-}

MQTTnet.Core/Internal/MqttApplicationMessageExtensions.cs

@@ -4,6 +4,17 @@ namespace MQTTnet.Core.Internal
 {
     internal static class MqttApplicationMessageExtensions
     {
+        public static MqttApplicationMessage ToApplicationMessage(this MqttPublishPacket publishPacket)
+        {
+            return new MqttApplicationMessage
+            { 
+                Topic = publishPacket.Topic,
+                Payload = publishPacket.Payload,
+                QualityOfServiceLevel = publishPacket.QualityOfServiceLevel,
+                Retain = publishPacket.Retain
+            };
+        }
+
         public static MqttPublishPacket ToPublishPacket(this MqttApplicationMessage applicationMessage)
         {
             if (applicationMessage == null)

MQTTnet.Core/Internal/TaskExtensions.cs

@@ -1,11 +1,74 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.Exceptions;
 
 namespace MQTTnet.Core.Internal
 {
-    internal static class TaskExtensions
+    public static class TaskExtensions
     {
-        public static void Forget(this Task task)
+        public static async Task TimeoutAfter(this Task task, TimeSpan timeout)
         {
+            using (var cancellationTokenSource = new CancellationTokenSource())
+            {
+                try
+                {
+                    var timeoutTask = Task.Delay(timeout, cancellationTokenSource.Token);
+                    var finishedTask = await Task.WhenAny(timeoutTask, task).ConfigureAwait(false);
+
+                    if (finishedTask == timeoutTask)
+                    {
+                        throw new MqttCommunicationTimedOutException();
+                    }
+
+                    if (task.IsCanceled)
+                    {
+                        throw new TaskCanceledException();
+                    }
+
+                    if (task.IsFaulted)
+                    {
+                        throw new MqttCommunicationException(task.Exception.GetBaseException());
+                    }
+                }
+                finally
+                {
+                    cancellationTokenSource.Cancel();
+                }
+            }
+        }
+
+        public static async Task<TResult> TimeoutAfter<TResult>(this Task<TResult> task, TimeSpan timeout)
+        {
+            using (var cancellationTokenSource = new CancellationTokenSource())
+            {
+                try
+                {
+                    var timeoutTask = Task.Delay(timeout, cancellationTokenSource.Token);
+                    var finishedTask = await Task.WhenAny(timeoutTask, task).ConfigureAwait(false);
+
+                    if (finishedTask == timeoutTask)
+                    {
+                        throw new MqttCommunicationTimedOutException();
+                    }
+
+                    if (task.IsCanceled)
+                    {
+                        throw new TaskCanceledException();
+                    }
+
+                    if (task.IsFaulted)
+                    {
+                        throw new MqttCommunicationException(task.Exception.GetBaseException());
+                    }
+
+                    return task.Result;
+                }
+                finally
+                {
+                    cancellationTokenSource.Cancel();
+                }
+            }
         }
     }
 }

MQTTnet.Core/MQTTnet.Core.csproj

@@ -5,30 +5,21 @@
     <AssemblyName>MQTTnet.Core</AssemblyName>
     <RootNamespace>MQTTnet.Core</RootNamespace>
     <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
-    <Description>MQTTnet is a .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</Description>
+    <DebugType>Full</DebugType>
-    <Product>MQTTnet</Product>
+    <Description></Description>
-    <Company>Christian Kratky</Company>
+    <Product></Product>
-    <Authors>Christian Kratky</Authors>
+    <Company></Company>
-    <Version>2.1.2.0</Version>
+    <Authors></Authors>
-    <PackageId>MQTTnet.Core</PackageId>
+    <Version>0.0.0.0</Version>
-    <Copyright>Copyright © Christian Kratky 2016-2017</Copyright>
+    <PackageId></PackageId>
-    <PackageProjectUrl>https://github.com/chkr1011/MQTTnet</PackageProjectUrl>
+    <Copyright></Copyright>
-    <PackageIconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</PackageIconUrl>
+    <PackageProjectUrl></PackageProjectUrl>
-    <RepositoryUrl>https://github.com/chkr1011/MQTTnet</RepositoryUrl>
+    <PackageIconUrl></PackageIconUrl>
-    <PackageTags>MQTT MQTTClient MQTTServer MQTTBroker Broker</PackageTags>
+    <RepositoryUrl></RepositoryUrl>
-    <FileVersion>2.1.2.0</FileVersion>
+    <PackageTags></PackageTags>
-    <AssemblyVersion>2.1.2.0</AssemblyVersion>
+    <FileVersion>2.5.3.0</FileVersion>
-    <PackageLicenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</PackageLicenseUrl>
+    <AssemblyVersion>2.5.3.0</AssemblyVersion>
+    <PackageLicenseUrl></PackageLicenseUrl>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|AnyCPU'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|x64'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x86'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x86'" />
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Any CPU|x86'" />
-
 </Project>

MQTTnet.Core/ManagedClient/IManagedMqttClient.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public interface IManagedMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher
+    {
+        bool IsConnected { get; }
+
+        event EventHandler<MqttClientConnectedEventArgs> Connected;
+        event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+
+        Task StartAsync(IManagedMqttClientOptions options);
+        Task StopAsync();
+
+        Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+        Task UnsubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+    }
+}

MQTTnet.Core/ManagedClient/IManagedMqttClientOptions.cs

@@ -0,0 +1,14 @@
+using System;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public interface IManagedMqttClientOptions
+    {
+        IMqttClientOptions ClientOptions { get; }
+
+        TimeSpan AutoReconnectDelay { get; }
+
+        IManagedMqttClientStorage Storage { get; }
+    }
+}

MQTTnet.Core/ManagedClient/IManagedMqttClientStorage.cs

@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public interface IManagedMqttClientStorage
+    {
+        Task SaveQueuedMessagesAsync(IList<MqttApplicationMessage> messages);
+
+        Task<IList<MqttApplicationMessage>> LoadQueuedMessagesAsync();
+    }
+}

MQTTnet.Core/ManagedClient/ManagedMqttClient.cs

@@ -0,0 +1,303 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Core.Client;
+using MQTTnet.Core.Diagnostics;
+using MQTTnet.Core.Exceptions;
+using MQTTnet.Core.Protocol;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public class ManagedMqttClient : IManagedMqttClient
+    {
+        private readonly ManagedMqttClientStorageManager _storageManager = new ManagedMqttClientStorageManager();
+        private readonly BlockingCollection<MqttApplicationMessage> _messageQueue = new BlockingCollection<MqttApplicationMessage>();
+        private readonly HashSet<TopicFilter> _subscriptions = new HashSet<TopicFilter>();
+
+        private readonly IMqttClient _mqttClient;
+        private readonly IMqttNetLogger _logger;
+
+        private CancellationTokenSource _connectionCancellationToken;
+        private CancellationTokenSource _publishingCancellationToken;
+
+        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 event EventHandler<MqttClientConnectedEventArgs> Connected;
+        public event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+        public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
+
+        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;
+            await _storageManager.SetStorageAsync(_options.Storage).ConfigureAwait(false);
+
+            if (_options.Storage != null)
+            {
+                var loadedMessages = await _options.Storage.LoadQueuedMessagesAsync().ConfigureAwait(false);
+                foreach (var loadedMessage in loadedMessages)
+                {
+                    _messageQueue.Add(loadedMessage);    
+                }
+            }
+
+            _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), _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()
+        {
+            _connectionCancellationToken?.Cancel(false);
+            _connectionCancellationToken = null;
+
+            _publishingCancellationToken?.Cancel(false);
+            _publishingCancellationToken = null;
+
+            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)
+            {
+                await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
+                _messageQueue.Add(applicationMessage);
+            }
+        }
+
+        public Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
+        {
+            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+
+            lock (_subscriptions)
+            {
+                foreach (var topicFilter in topicFilters)
+                {
+                    if (_subscriptions.Add(topicFilter))
+                    {
+                        _subscriptionsNotPushed = true;
+                    }
+                }
+            }
+
+            return Task.FromResult(0);
+        }
+
+        public Task UnsubscribeAsync(IEnumerable<TopicFilter> topicFilters)
+        {
+            lock (_subscriptions)
+            {
+                foreach (var topicFilter in topicFilters)
+                {
+                    if (_subscriptions.Remove(topicFilter))
+                    {
+                        _subscriptionsNotPushed = true;
+                    }
+                }
+            }
+
+            return Task.FromResult(0);
+        }
+
+        private async Task MaintainConnectionAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    var connectionState = await ReconnectIfRequiredAsync().ConfigureAwait(false);
+                    if (connectionState == ReconnectionResult.NotConnected)
+                    {
+                        _publishingCancellationToken?.Cancel(false);
+                        _publishingCancellationToken = null;
+
+                        await Task.Delay(_options.AutoReconnectDelay, cancellationToken).ConfigureAwait(false);
+                        continue;
+                    }
+
+                    if (connectionState == ReconnectionResult.Reconnected || _subscriptionsNotPushed)
+                    {
+                        await PushSubscriptionsAsync();
+
+                        _publishingCancellationToken = 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 PublishQueuedMessagesAsync(_publishingCancellationToken.Token), _publishingCancellationToken.Token).ConfigureAwait(false);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+
+                        continue;
+                    }
+
+                    if (connectionState == ReconnectionResult.StillConnected)
+                    {
+                        await Task.Delay(TimeSpan.FromSeconds(1), _connectionCancellationToken.Token).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.");
+            }
+            finally
+            {
+                await _mqttClient.DisconnectAsync().ConfigureAwait(false);
+                _logger.Info<ManagedMqttClient>("Stopped");
+            }
+        }
+
+        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);
+                    await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            finally
+            {
+                _logger.Info<ManagedMqttClient>("Stopped publishing messages");
+            }
+        }
+
+        private async Task TryPublishQueuedMessageAsync(MqttApplicationMessage message)
+        {
+            try
+            {
+                await _mqttClient.PublishAsync(message).ConfigureAwait(false);
+            }
+            catch (MqttCommunicationException exception)
+            {
+                _logger.Warning<ManagedMqttClient>(exception, "Publishing application message failed.");
+
+                if (message.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
+                {
+                    _messageQueue.Add(message);
+                }
+            }
+            catch (Exception exception)
+            {
+                _logger.Error<ManagedMqttClient>(exception, "Unhandled exception while publishing queued application message.");
+            }
+        }
+
+        private async Task PushSubscriptionsAsync()
+        {
+            _logger.Info<ManagedMqttClient>(nameof(ManagedMqttClient), "Synchronizing subscriptions");
+
+            List<TopicFilter> subscriptions;
+            lock (_subscriptions)
+            {
+                subscriptions = _subscriptions.ToList();
+                _subscriptionsNotPushed = false;
+            }
+
+            if (!_subscriptions.Any())
+            {
+                return;
+            }
+
+            try
+            {
+                await _mqttClient.SubscribeAsync(subscriptions).ConfigureAwait(false);
+            }
+            catch (Exception exception)
+            {
+                _logger.Warning<ManagedMqttClient>(exception, "Synchronizing subscriptions failed");
+                _subscriptionsNotPushed = true;
+            }
+        }
+
+        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);
+        }
+    }
+}

MQTTnet.Core/ManagedClient/ManagedMqttClientExtensions.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core.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 UnsubscribeAsync(this IManagedMqttClient managedClient, params TopicFilter[] topicFilters)
+        {
+            if (managedClient == null) throw new ArgumentNullException(nameof(managedClient));
+
+            return managedClient.UnsubscribeAsync(topicFilters);
+        }
+    }
+}

MQTTnet.Core/ManagedClient/ManagedMqttClientOptions.cs

@@ -0,0 +1,14 @@
+using System;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public class ManagedMqttClientOptions : IManagedMqttClientOptions
+    {
+        public IMqttClientOptions ClientOptions { get; set; }
+
+        public TimeSpan AutoReconnectDelay { get; set; } = TimeSpan.FromSeconds(5);
+
+        public IManagedMqttClientStorage Storage { get; set; }
+    }
+}

MQTTnet.Core/ManagedClient/ManagedMqttClientOptionsBuilder.cs

@@ -0,0 +1,49 @@
+using System;
+using MQTTnet.Core.Client;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public class ManagedMqttClientOptionsBuilder
+    {
+        private readonly ManagedMqttClientOptions _options = new ManagedMqttClientOptions();
+
+        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)
+        {
+            _options.ClientOptions = value ?? throw new ArgumentNullException(nameof(value));
+            return this;
+        }
+
+        public ManagedMqttClientOptionsBuilder WithClientOptions(Action<MqttClientOptionsBuilder> options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            var builder = new MqttClientOptionsBuilder();
+            options(builder);
+            _options.ClientOptions = builder.Build();
+
+            return this;
+        }
+
+        public ManagedMqttClientOptions Build()
+        {
+            if (_options.ClientOptions == null)
+            {
+                throw new InvalidOperationException("The ClientOptions cannot be null.");
+            }
+
+            return _options;
+        }
+    }
+}

MQTTnet.Core/ManagedClient/ManagedMqttClientStorageManager.cs

@@ -0,0 +1,75 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Core.ManagedClient
+{
+    public class ManagedMqttClientStorageManager
+    {
+        private readonly List<MqttApplicationMessage> _applicationMessages = new List<MqttApplicationMessage>();
+        private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);
+        private IManagedMqttClientStorage _storage;
+
+        public async Task SetStorageAsync(IManagedMqttClientStorage storage)
+        {
+            await _semaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                _storage = storage;
+            }
+            finally
+            {
+                _semaphore.Release();
+            }
+        }
+
+        public async Task AddAsync(MqttApplicationMessage applicationMessage)
+        {
+            await _semaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                if (_storage == null)
+                {
+                    return;
+                }
+
+                _applicationMessages.Add(applicationMessage);
+                await SaveAsync().ConfigureAwait(false);
+            }
+            finally
+            {
+                _semaphore.Release();
+            }
+        }
+
+        public async Task RemoveAsync(MqttApplicationMessage applicationMessage)
+        {
+            await _semaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                if (_storage == null)
+                {
+                    return;
+                }
+
+                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);
+        }
+    }
+}