Use the data converter only when creating packets.

Source/MQTTnet/Client/Disconnecting/MqttClientDisconnectReason.cs

@@ -12,7 +12,7 @@
         ServerBusy = 137,
         ServerShuttingDown = 139,
         BadAuthenticationMethod = 140,
-        KeepaliveTimeout = 141,
+        KeepAliveTimeout = 141,
         SessionTakenOver = 142,
         TopicFilterInvalid = 143,
         TopicNameInvalid = 144,

Source/MQTTnet/Client/MqttClient.cs

@@ -167,7 +167,7 @@ namespace MQTTnet.Client
 
         public Task PingAsync(CancellationToken cancellationToken)
         {
-            return SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket(), cancellationToken);
+            return SendAndReceiveAsync<MqttPingRespPacket>(MqttPingReqPacket.Instance, cancellationToken);
         }
 
         public Task SendExtendedAuthenticationExchangeDataAsync(MqttExtendedAuthenticationExchangeData data, CancellationToken cancellationToken)
@@ -650,11 +650,8 @@ namespace MQTTnet.Client
 
                         if (!eventArgs.ProcessingFailed)
                         {
-                            await SendAsync(new MqttPubAckPacket
+                            var pubAckPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePubAckPacket(publishPacket, eventArgs.ReasonCode);
-                            {
+                            await SendAsync(pubAckPacket, cancellationToken).ConfigureAwait(false);
-                                PacketIdentifier = publishPacket.PacketIdentifier,
-                                ReasonCode = (MqttPubAckReasonCode)eventArgs.ReasonCode
-                            }, cancellationToken).ConfigureAwait(false);
                         }
                     }
                     else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
@@ -663,11 +660,8 @@ namespace MQTTnet.Client
 
                         if (!eventArgs.ProcessingFailed)
                         {
-                            await SendAsync(new MqttPubRecPacket
+                            var pubRecPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePubRecPacket(publishPacket, eventArgs.ReasonCode);
-                            {
+                            await SendAsync(pubRecPacket, cancellationToken).ConfigureAwait(false);
-                                PacketIdentifier = publishPacket.PacketIdentifier,
-                                ReasonCode = (MqttPubRecReasonCode)eventArgs.ReasonCode
-                            }, cancellationToken).ConfigureAwait(false);
                         }
                     }
                     else
@@ -691,11 +685,8 @@ namespace MQTTnet.Client
             {
                 // The packet is unknown. Probably due to a restart of the client.
                 // So wen send this to the server to trigger a full resend of the message.
-                return SendAsync(new MqttPubRelPacket
+                var pubRelPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePubRelPacket(pubRecPacket, MqttApplicationMessageReceivedReasonCode.PacketIdentifierNotFound);
-                {
+                return SendAsync(pubRelPacket, cancellationToken);
-                    PacketIdentifier = pubRecPacket.PacketIdentifier,
-                    ReasonCode = MqttPubRelReasonCode.PacketIdentifierNotFound
-                }, cancellationToken);
             }
 
             return PlatformAbstractionLayer.CompletedTask;
@@ -703,11 +694,8 @@ namespace MQTTnet.Client
 
         Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket, CancellationToken cancellationToken)
         {
-            return SendAsync(new MqttPubCompPacket
+            var pubCompPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePubCompPacket(pubRelPacket, MqttApplicationMessageReceivedReasonCode.Success);
-            {
+            return SendAsync(pubCompPacket, cancellationToken);
-                PacketIdentifier = pubRelPacket.PacketIdentifier,
-                ReasonCode = MqttPubCompReasonCode.Success
-            }, cancellationToken);
         }
 
         Task ProcessReceivedDisconnectPacket(MqttDisconnectPacket disconnectPacket)
@@ -740,14 +728,14 @@ namespace MQTTnet.Client
         {
             // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
             await SendAsync(publishPacket, cancellationToken).ConfigureAwait(false);
-            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(null);
+            return _adapter.PacketFormatterAdapter.DataConverter.CreateClientPublishResult(null);
         }
 
         async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
         {
             publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();
             var response = await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
-            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(response);
+            return _adapter.PacketFormatterAdapter.DataConverter.CreateClientPublishResult(response);
         }
 
         async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
@@ -756,15 +744,11 @@ namespace MQTTnet.Client
 
             var pubRecPacket = await SendAndReceiveAsync<MqttPubRecPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
 
-            var pubRelPacket = new MqttPubRelPacket
+            var pubRelPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePubRelPacket(pubRecPacket, MqttApplicationMessageReceivedReasonCode.Success);
-            {
-                PacketIdentifier = publishPacket.PacketIdentifier,
-                ReasonCode = MqttPubRelReasonCode.Success
-            };
             
             var pubCompPacket = await SendAndReceiveAsync<MqttPubCompPacket>(pubRelPacket, cancellationToken).ConfigureAwait(false);
 
-            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(pubRecPacket, pubCompPacket);
+            return _adapter.PacketFormatterAdapter.DataConverter.CreateClientPublishResult(pubRecPacket, pubCompPacket);
         }
 
         async Task<MqttApplicationMessageReceivedEventArgs> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)

Source/MQTTnet/Formatter/IMqttDataConverter.cs

@@ -14,23 +14,31 @@ namespace MQTTnet.Formatter
 {
     public interface IMqttDataConverter
     {
-        MqttPublishPacket CreatePublishPacket(MqttApplicationMessage applicationMessage);
-
-        MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket);
-
-        MqttBasePacket CreatePubRecPacket(MqttPublishPacket publishPacket);
-
         MqttApplicationMessage CreateApplicationMessage(MqttPublishPacket publishPacket);
 
         MqttClientAuthenticateResult CreateClientConnectResult(MqttConnAckPacket connAckPacket);
 
+        MqttClientPublishResult CreateClientPublishResult(MqttPubAckPacket pubAckPacket);
+
+        MqttClientPublishResult CreateClientPublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket);
+        
+        MqttClientSubscribeResult CreateClientSubscribeResult(MqttSubscribePacket subscribePacket, MqttSubAckPacket subAckPacket);
+        
+        MqttClientUnsubscribeResult CreateClientUnsubscribeResult(MqttUnsubscribePacket unsubscribePacket, MqttUnsubAckPacket unsubAckPacket);
+
         MqttConnectPacket CreateConnectPacket(MqttApplicationMessage willApplicationMessage, IMqttClientOptions options);
 
         MqttConnAckPacket CreateConnAckPacket(MqttConnectionValidatorContext connectionValidatorContext);
         
-        MqttClientSubscribeResult CreateClientSubscribeResult(MqttSubscribePacket subscribePacket, MqttSubAckPacket subAckPacket);
+        MqttPublishPacket CreatePublishPacket(MqttApplicationMessage applicationMessage);
 
-        MqttClientUnsubscribeResult CreateClientUnsubscribeResult(MqttUnsubscribePacket unsubscribePacket, MqttUnsubAckPacket unsubAckPacket);
+        MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode);
+        
+        MqttPubRecPacket CreatePubRecPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode);
+
+        MqttPubCompPacket CreatePubCompPacket(MqttPubRelPacket pubRelPacket, MqttApplicationMessageReceivedReasonCode reasonCode);
+        
+        MqttPubRelPacket CreatePubRelPacket(MqttPubRecPacket pubRecPacket, MqttApplicationMessageReceivedReasonCode reasonCode);
         
         MqttSubscribePacket CreateSubscribePacket(MqttClientSubscribeOptions options);
 
@@ -41,9 +49,5 @@ namespace MQTTnet.Formatter
         MqttUnsubAckPacket CreateUnsubAckPacket(MqttUnsubscribePacket unsubscribePacket, List<MqttUnsubscribeReasonCode> reasonCodes);
 
         MqttDisconnectPacket CreateDisconnectPacket(MqttClientDisconnectOptions options);
-
-        MqttClientPublishResult CreatePublishResult(MqttPubAckPacket pubAckPacket);
-
-        MqttClientPublishResult CreatePublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket);
     }
 }

Source/MQTTnet/Formatter/V3/MqttV310DataConverter.cs

@@ -31,21 +31,43 @@ namespace MQTTnet.Formatter.V3
             };
         }
 
-        public MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket)
+        public MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
         {
+            if (publishPacket == null) throw new ArgumentNullException(nameof(publishPacket));
+            
             return new MqttPubAckPacket
             {
-                PacketIdentifier = publishPacket.PacketIdentifier,
+                PacketIdentifier = publishPacket.PacketIdentifier
-                ReasonCode = MqttPubAckReasonCode.Success
             };
         }
 
-        public MqttBasePacket CreatePubRecPacket(MqttPublishPacket publishPacket)
+        public MqttPubRecPacket CreatePubRecPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
         {
+            if (publishPacket == null) throw new ArgumentNullException(nameof(publishPacket));
+            
             return new MqttPubRecPacket
             {
-                PacketIdentifier = publishPacket.PacketIdentifier,
+                PacketIdentifier = publishPacket.PacketIdentifier
-                ReasonCode = MqttPubRecReasonCode.Success
+            };
+        }
+
+        public MqttPubCompPacket CreatePubCompPacket(MqttPubRelPacket pubRelPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
+        {
+            if (pubRelPacket == null) throw new ArgumentNullException(nameof(pubRelPacket));
+            
+            return new MqttPubCompPacket
+            {
+                PacketIdentifier = pubRelPacket.PacketIdentifier
+            };
+        }
+
+        public MqttPubRelPacket CreatePubRelPacket(MqttPubRecPacket pubRecPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
+        {
+            if (pubRecPacket == null) throw new ArgumentNullException(nameof(pubRecPacket));
+            
+            return new MqttPubRelPacket
+            {
+                PacketIdentifier = pubRecPacket.PacketIdentifier
             };
         }
 
@@ -58,7 +80,8 @@ namespace MQTTnet.Formatter.V3
                 Topic = publishPacket.Topic,
                 Payload = publishPacket.Payload,
                 QualityOfServiceLevel = publishPacket.QualityOfServiceLevel,
-                Retain = publishPacket.Retain
+                Retain = publishPacket.Retain,
+                Dup = publishPacket.Dup
             };
         }
 
@@ -184,6 +207,9 @@ namespace MQTTnet.Formatter.V3
 
         public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, Server.MqttClientSubscribeResult subscribeResult)
         {
+            if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
+            if (subscribeResult == null) throw new ArgumentNullException(nameof(subscribeResult));
+
             var subackPacket = new MqttSubAckPacket
             {
                 PacketIdentifier = subscribePacket.PacketIdentifier
@@ -206,6 +232,9 @@ namespace MQTTnet.Formatter.V3
 
         public MqttUnsubAckPacket CreateUnsubAckPacket(MqttUnsubscribePacket unsubscribePacket, List<MqttUnsubscribeReasonCode> reasonCodes)
         {
+            if (unsubscribePacket == null) throw new ArgumentNullException(nameof(unsubscribePacket));
+            if (reasonCodes == null) throw new ArgumentNullException(nameof(reasonCodes));
+
             return new MqttUnsubAckPacket
             {
                 PacketIdentifier = unsubscribePacket.PacketIdentifier,
@@ -223,7 +252,7 @@ namespace MQTTnet.Formatter.V3
             return new MqttDisconnectPacket();
         }
 
-        public MqttClientPublishResult CreatePublishResult(MqttPubAckPacket pubAckPacket)
+        public MqttClientPublishResult CreateClientPublishResult(MqttPubAckPacket pubAckPacket)
         {
             return new MqttClientPublishResult
             {
@@ -232,7 +261,7 @@ namespace MQTTnet.Formatter.V3
             };
         }
 
-        public MqttClientPublishResult CreatePublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket)
+        public MqttClientPublishResult CreateClientPublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket)
         {
             if (pubRecPacket == null || pubCompPacket == null)
             {

Source/MQTTnet/Formatter/V5/MqttV500DataConverter.cs

@@ -15,7 +15,7 @@ using MqttClientSubscribeResult = MQTTnet.Client.Subscribing.MqttClientSubscribe
 
 namespace MQTTnet.Formatter.V5
 {
-    public class MqttV500DataConverter : IMqttDataConverter
+    public sealed class MqttV500DataConverter : IMqttDataConverter
     {
         public MqttPublishPacket CreatePublishPacket(MqttApplicationMessage applicationMessage)
         {
@@ -27,7 +27,7 @@ namespace MQTTnet.Formatter.V5
                 Payload = applicationMessage.Payload,
                 QualityOfServiceLevel = applicationMessage.QualityOfServiceLevel,
                 Retain = applicationMessage.Retain,
-                Dup = false,
+                Dup = applicationMessage.Dup,
                 Properties = new MqttPublishPacketProperties
                 {
                     ContentType = applicationMessage.ContentType,
@@ -49,32 +49,61 @@ namespace MQTTnet.Formatter.V5
             return packet;
         }
 
-        public MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket)
+        public MqttPubAckPacket CreatePubAckPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
         {
+            if (publishPacket == null) throw new ArgumentNullException(nameof(publishPacket));
+
             return new MqttPubAckPacket
             {
                 PacketIdentifier = publishPacket.PacketIdentifier,
-                ReasonCode = MqttPubAckReasonCode.Success
+                ReasonCode = (MqttPubAckReasonCode)(int)reasonCode
             };
         }
 
-        public MqttBasePacket CreatePubRecPacket(MqttPublishPacket publishPacket)
+        public MqttPubRecPacket CreatePubRecPacket(MqttPublishPacket publishPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
         {
+            if (publishPacket == null) throw new ArgumentNullException(nameof(publishPacket));
+
             return new MqttPubRecPacket
             {
                 PacketIdentifier = publishPacket.PacketIdentifier,
-                ReasonCode = MqttPubRecReasonCode.Success
+                ReasonCode = (MqttPubRecReasonCode)(int)reasonCode
+            };
+        }
+
+        public MqttPubCompPacket CreatePubCompPacket(MqttPubRelPacket pubRelPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
+        {
+            if (pubRelPacket == null) throw new ArgumentNullException(nameof(pubRelPacket));
+
+            return new MqttPubCompPacket
+            {
+                PacketIdentifier = pubRelPacket.PacketIdentifier,
+                ReasonCode = (MqttPubCompReasonCode)(int)reasonCode
+            };
+        }
+
+        public MqttPubRelPacket CreatePubRelPacket(MqttPubRecPacket pubRecPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
+        {
+            if (pubRecPacket == null) throw new ArgumentNullException(nameof(pubRecPacket));
+
+            return new MqttPubRelPacket
+            {
+                PacketIdentifier = pubRecPacket.PacketIdentifier,
+                ReasonCode = (MqttPubRelReasonCode)(int)reasonCode
             };
         }
 
         public MqttApplicationMessage CreateApplicationMessage(MqttPublishPacket publishPacket)
         {
+            if (publishPacket == null) throw new ArgumentNullException(nameof(publishPacket));
+
             return new MqttApplicationMessage
             {
                 Topic = publishPacket.Topic,
                 Payload = publishPacket.Payload,
                 QualityOfServiceLevel = publishPacket.QualityOfServiceLevel,
                 Retain = publishPacket.Retain,
+                Dup = publishPacket.Dup,
                 ResponseTopic = publishPacket.Properties?.ResponseTopic,
                 ContentType = publishPacket.Properties?.ContentType,
                 CorrelationData = publishPacket.Properties?.CorrelationData,
@@ -93,7 +122,7 @@ namespace MQTTnet.Formatter.V5
             return new MqttClientAuthenticateResult
             {
                 IsSessionPresent = connAckPacket.IsSessionPresent,
-                ResultCode = (MqttClientConnectResultCode)connAckPacket.ReasonCode.Value,
+                ResultCode = (MqttClientConnectResultCode)(int)(connAckPacket.ReasonCode ?? 0),
                 WildcardSubscriptionAvailable = connAckPacket.Properties?.WildcardSubscriptionAvailable,
                 RetainAvailable = connAckPacket.Properties?.RetainAvailable,
                 AssignedClientIdentifier = connAckPacket.Properties?.AssignedClientIdentifier,
@@ -144,6 +173,8 @@ namespace MQTTnet.Formatter.V5
 
         public MqttConnAckPacket CreateConnAckPacket(MqttConnectionValidatorContext connectionValidatorContext)
         {
+            if (connectionValidatorContext == null) throw new ArgumentNullException(nameof(connectionValidatorContext));
+
             return new MqttConnAckPacket
             {
                 ReasonCode = connectionValidatorContext.ReasonCode,
@@ -213,6 +244,9 @@ namespace MQTTnet.Formatter.V5
 
         public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, Server.MqttClientSubscribeResult subscribeResult)
         {
+            if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
+            if (subscribeResult == null) throw new ArgumentNullException(nameof(subscribeResult));
+
             var subackPacket = new MqttSubAckPacket
             {
                 PacketIdentifier = subscribePacket.PacketIdentifier
@@ -240,6 +274,9 @@ namespace MQTTnet.Formatter.V5
 
         public MqttUnsubAckPacket CreateUnsubAckPacket(MqttUnsubscribePacket unsubscribePacket, List<MqttUnsubscribeReasonCode> reasonCodes)
         {
+            if (unsubscribePacket == null) throw new ArgumentNullException(nameof(unsubscribePacket));
+            if (reasonCodes == null) throw new ArgumentNullException(nameof(reasonCodes));
+
             return new MqttUnsubAckPacket
             {
                 PacketIdentifier = unsubscribePacket.PacketIdentifier,
@@ -263,7 +300,7 @@ namespace MQTTnet.Formatter.V5
             return packet;
         }
 
-        public MqttClientPublishResult CreatePublishResult(MqttPubAckPacket pubAckPacket)
+        public MqttClientPublishResult CreateClientPublishResult(MqttPubAckPacket pubAckPacket)
         {
             var result = new MqttClientPublishResult
             {
@@ -276,7 +313,7 @@ namespace MQTTnet.Formatter.V5
             {
                 // QoS 0 has no response. So we treat it as a success always.
                 // Both enums have the same values. So it can be easily converted.
-                result.ReasonCode = (MqttClientPublishReasonCode)pubAckPacket.ReasonCode;
+                result.ReasonCode = (MqttClientPublishReasonCode)(int)(pubAckPacket.ReasonCode ?? 0);
 
                 result.PacketIdentifier = pubAckPacket.PacketIdentifier;
             }
@@ -284,7 +321,7 @@ namespace MQTTnet.Formatter.V5
             return result;
         }
 
-        public MqttClientPublishResult CreatePublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket)
+        public MqttClientPublishResult CreateClientPublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket)
         {
             if (pubRecPacket == null || pubCompPacket == null)
             {
@@ -317,7 +354,7 @@ namespace MQTTnet.Formatter.V5
             if (pubRecPacket.ReasonCode.HasValue)
             {
                 // Both enums share the same values.
-                result.ReasonCode = (MqttClientPublishReasonCode)pubRecPacket.ReasonCode.Value;
+                result.ReasonCode = (MqttClientPublishReasonCode)(pubRecPacket.ReasonCode ?? 0);
             }
 
             return result;

Source/MQTTnet/MqttApplicationMessageReceivedReasonCode.cs

@@ -9,6 +9,7 @@
         NotAuthorized = 135,
         TopicNameInvalid = 144,
         PacketIdentifierInUse = 145,
+        PacketIdentifierNotFound = 146,
         QuotaExceeded = 151,
         PayloadFormatInvalid = 153
     }

Source/MQTTnet/Packets/MqttPingReqPacket.cs

@@ -3,7 +3,7 @@
     public sealed class MqttPingReqPacket : MqttBasePacket
     {
         // This is a minor performance improvement.
-        public static MqttPingReqPacket Instance = new MqttPingReqPacket();
+        public static readonly MqttPingReqPacket Instance = new MqttPingReqPacket();
 
         public override string ToString()
         {

Source/MQTTnet/Packets/MqttPingRespPacket.cs

@@ -3,7 +3,7 @@
     public sealed class MqttPingRespPacket : MqttBasePacket
     {
         // This is a minor performance improvement.
-        public static MqttPingRespPacket Instance = new MqttPingRespPacket();
+        public static readonly MqttPingRespPacket Instance = new MqttPingRespPacket();
 
         public override string ToString()
         {

Source/MQTTnet/Server/MqttClientConnection.cs

@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Client.Disconnecting;
 
 namespace MQTTnet.Server
 {
@@ -42,7 +43,7 @@ namespace MQTTnet.Server
         long _sentPacketsCount = 1; // Start with 1 because the CONNECT packet is not counted anywhere.
         long _receivedApplicationMessagesCount;
         long _sentApplicationMessagesCount;
-        MqttDisconnectReasonCode _disconnectReason;
+        MqttClientDisconnectReason _disconnectReason;
 
         public MqttClientConnection(MqttConnectPacket connectPacket,
             IMqttChannelAdapter channelAdapter,
@@ -84,12 +85,12 @@ namespace MQTTnet.Server
 
         public MqttClientSession Session { get; }
 
-        public async Task StopAsync(MqttDisconnectReasonCode reason)
+        public async Task StopAsync(MqttClientDisconnectReason reason)
         {
             Status = MqttClientConnectionStatus.Finalizing;
             _disconnectReason = reason;
 
-            if (reason == MqttDisconnectReasonCode.SessionTakenOver || reason == MqttDisconnectReasonCode.KeepAliveTimeout)
+            if (reason == MqttClientDisconnectReason.SessionTakenOver || reason == MqttClientDisconnectReason.KeepAliveTimeout)
             {
                 // Is is very important to send the DISCONNECT packet here BEFORE cancelling the
                 // token because the entire connection is closed (disposed) as soon as the cancellation
@@ -97,10 +98,18 @@ namespace MQTTnet.Server
                 // at the client!
                 try
                 {
-                    await _channelAdapter.SendPacketAsync(new MqttDisconnectPacket
+                    var disconnectOptions = new MqttClientDisconnectOptions
                     {
-                        ReasonCode = reason
+                        ReasonCode = reason,
-                    }, CancellationToken.None).ConfigureAwait(false);
+                        ReasonString = reason.ToString()
+                    };
+                    
+                    var disconnectPacket = _channelAdapter.PacketFormatterAdapter.DataConverter.CreateDisconnectPacket(disconnectOptions);
+
+                    using (var timeout = new CancellationTokenSource(_serverOptions.DefaultCommunicationTimeout))
+                    {
+                        await _channelAdapter.SendPacketAsync(disconnectPacket, timeout.Token).ConfigureAwait(false);
+                    }
                 }
                 catch (Exception exception)
                 {
@@ -235,7 +244,7 @@ namespace MQTTnet.Server
             }
             finally
             {
-                if (_disconnectReason == MqttDisconnectReasonCode.SessionTakenOver)
+                if (_disconnectReason == MqttClientDisconnectReason.SessionTakenOver)
                 {
                     disconnectType = MqttClientDisconnectType.Takeover;
                 }
@@ -277,12 +286,7 @@ namespace MQTTnet.Server
 
         Task HandleIncomingPubRelPacketAsync(MqttPubRelPacket pubRelPacket, CancellationToken cancellationToken)
         {
-            var pubCompPacket = new MqttPubCompPacket
+            var pubCompPacket = _channelAdapter.PacketFormatterAdapter.DataConverter.CreatePubCompPacket(pubRelPacket, MqttApplicationMessageReceivedReasonCode.Success);
-            {
-                PacketIdentifier = pubRelPacket.PacketIdentifier,
-                ReasonCode = MqttPubCompReasonCode.Success
-            };
-
             return SendAsync(pubCompPacket, cancellationToken);
         }
 
@@ -327,12 +331,12 @@ namespace MQTTnet.Server
                     }
                 case MqttQualityOfServiceLevel.AtLeastOnce:
                     {
-                        var pubAckPacket = _dataConverter.CreatePubAckPacket(publishPacket);
+                        var pubAckPacket = _dataConverter.CreatePubAckPacket(publishPacket, MqttApplicationMessageReceivedReasonCode.Success);
                         return SendAsync(pubAckPacket, cancellationToken);
                     }
                 case MqttQualityOfServiceLevel.ExactlyOnce:
                     {
-                        var pubRecPacket = _dataConverter.CreatePubRecPacket(publishPacket);
+                        var pubRecPacket = _dataConverter.CreatePubRecPacket(publishPacket, MqttApplicationMessageReceivedReasonCode.Success);
                         return SendAsync(pubRecPacket, cancellationToken);
                     }
                 default:
@@ -441,13 +445,10 @@ namespace MQTTnet.Server
                         using (var awaiter2 = _packetDispatcher.AddAwaiter<MqttPubCompPacket>(publishPacket.PacketIdentifier))
                         {
                             await SendAsync(publishPacket, cancellationToken).ConfigureAwait(false);
-                            await awaiter1.WaitOneAsync(_serverOptions.DefaultCommunicationTimeout).ConfigureAwait(false);
+                            var pubRecPacket = await awaiter1.WaitOneAsync(_serverOptions.DefaultCommunicationTimeout).ConfigureAwait(false);
 
-                            await SendAsync(new MqttPubRelPacket
+                            var pubRelPacket = _channelAdapter.PacketFormatterAdapter.DataConverter.CreatePubRelPacket(pubRecPacket, MqttApplicationMessageReceivedReasonCode.Success);
-                            {
+                            await SendAsync(pubRelPacket, cancellationToken).ConfigureAwait(false);
-                                PacketIdentifier = publishPacket.PacketIdentifier,
-                                ReasonCode = MqttPubRelReasonCode.Success
-                            }, cancellationToken).ConfigureAwait(false);
 
                             await awaiter2.WaitOneAsync(_serverOptions.DefaultCommunicationTimeout).ConfigureAwait(false);
                         }

Source/MQTTnet/Server/MqttClientSessionsManager.cs

@@ -12,6 +12,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Client.Disconnecting;
 using OperationCanceledException = System.OperationCanceledException;
 
 namespace MQTTnet.Server
@@ -121,7 +122,7 @@ namespace MQTTnet.Server
 
             foreach (var connection in connections)
             {
-                await connection.StopAsync(MqttDisconnectReasonCode.NormalDisconnection).ConfigureAwait(false);
+                await connection.StopAsync(MqttClientDisconnectReason.NormalDisconnection).ConfigureAwait(false);
             }
         }
 
@@ -211,7 +212,7 @@ namespace MQTTnet.Server
 
             if (connection != null)
             {
-                await connection.StopAsync(MqttDisconnectReasonCode.NormalDisconnection).ConfigureAwait(false);
+                await connection.StopAsync(MqttClientDisconnectReason.NormalDisconnection).ConfigureAwait(false);
             }
             
             _logger.Verbose("Session for client '{0}' deleted.", clientId);
@@ -301,7 +302,7 @@ namespace MQTTnet.Server
                         {
                             if (clientConnection != null)
                             {
-                                await clientConnection.StopAsync(MqttDisconnectReasonCode.NormalDisconnection).ConfigureAwait(false);
+                                await clientConnection.StopAsync(MqttClientDisconnectReason.NormalDisconnection).ConfigureAwait(false);
                             }
                         }
 
@@ -424,7 +425,7 @@ namespace MQTTnet.Server
                     _connections[connectPacket.ClientId] = connection;
                 }
 
-                existingConnection?.StopAsync(MqttDisconnectReasonCode.SessionTakenOver).GetAwaiter().GetResult();
+                existingConnection?.StopAsync(MqttClientDisconnectReason.SessionTakenOver).GetAwaiter().GetResult();
 
                 return connection;
             }

Source/MQTTnet/Server/MqttServerKeepAliveMonitor.cs

@@ -3,8 +3,8 @@ using MQTTnet.Internal;
 using System;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Client.Disconnecting;
 using MQTTnet.Implementations;
-using MQTTnet.Protocol;
 
 namespace MQTTnet.Server
 {
@@ -108,7 +108,7 @@ namespace MQTTnet.Server
                 // We do not need to wait for the task so no await is needed.
                 // Also the internal state of the connection must be swapped to "Finalizing" because the
                 // next iteration of the keep alive timer happens.
-                var _ = connection.StopAsync(MqttDisconnectReasonCode.KeepAliveTimeout);
+                var _ = connection.StopAsync(MqttClientDisconnectReason.KeepAliveTimeout);
             }
             catch (Exception exception)
             {

Source/MQTTnet/Server/Status/MqttClientStatus.cs

@@ -1,7 +1,7 @@
 using MQTTnet.Formatter;
 using System;
 using System.Threading.Tasks;
-using MQTTnet.Protocol;
+using MQTTnet.Client.Disconnecting;
 
 namespace MQTTnet.Server.Status
 {
@@ -46,7 +46,7 @@ namespace MQTTnet.Server.Status
 
         public Task DisconnectAsync()
         {
-            return _connection.StopAsync(MqttDisconnectReasonCode.NormalDisconnection);
+            return _connection.StopAsync(MqttClientDisconnectReason.NormalDisconnection);
         }
 
         public void ResetStatistics()