diff --git a/Frameworks/MQTTnet.UniversalWindows/Implementations/MqttServerAdapter.cs b/Frameworks/MQTTnet.UniversalWindows/Implementations/MqttServerAdapter.cs
index 373cdac..fc38fdf 100644
--- a/Frameworks/MQTTnet.UniversalWindows/Implementations/MqttServerAdapter.cs
+++ b/Frameworks/MQTTnet.UniversalWindows/Implementations/MqttServerAdapter.cs
@@ -30,6 +30,7 @@ namespace MQTTnet.Implementations
             if (options.DefaultEndpointOptions.IsEnabled)
             {
                 _defaultEndpointSocket = new StreamSocketListener();
+                _defaultEndpointSocket.Control.NoDelay = true;
                 await _defaultEndpointSocket.BindServiceNameAsync(options.GetDefaultEndpointPort().ToString(), SocketProtectionLevel.PlainSocket);
                 _defaultEndpointSocket.ConnectionReceived += AcceptDefaultEndpointConnectionsAsync;
             }
@@ -57,6 +58,8 @@ namespace MQTTnet.Implementations
         {
             try
             {
+                args.Socket.Control.NoDelay = true;
+
                 var clientAdapter = _mqttCommunicationAdapterFactory.CreateServerMqttCommunicationAdapter(new MqttTcpChannel(args.Socket));
                 ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
             }
diff --git a/MQTTnet.Core/Server/MqttClientSession.cs b/MQTTnet.Core/Server/MqttClientSession.cs
index e1f8457..903b330 100644
--- a/MQTTnet.Core/Server/MqttClientSession.cs
+++ b/MQTTnet.Core/Server/MqttClientSession.cs
@@ -142,51 +142,65 @@ namespace MQTTnet.Core.Server
             }
         }
 
-        private async Task ProcessReceivedPacketAsync(IMqttCommunicationAdapter adapter, MqttBasePacket packet, CancellationToken cancellationToken)
+        private Task ProcessReceivedPacketAsync(IMqttCommunicationAdapter adapter, MqttBasePacket packet, CancellationToken cancellationToken)
         {
-            if (packet is MqttSubscribePacket subscribePacket)
+            if (packet is MqttPingReqPacket)
             {
-                var subscribeResult = _subscriptionsManager.Subscribe(subscribePacket);
-                await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, subscribeResult.ResponsePacket);
-                EnqueueRetainedMessages(subscribePacket);
-
-                if (subscribeResult.CloseConnection)
-                {
-                    await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttDisconnectPacket());
-                    Stop();
-                }
+                return adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttPingRespPacket());
             }
-            else if (packet is MqttUnsubscribePacket unsubscribePacket)
+
+            if (packet is MqttPublishPacket publishPacket)
             {
-                await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, _subscriptionsManager.Unsubscribe(unsubscribePacket));
+                return HandleIncomingPublishPacketAsync(adapter, publishPacket, cancellationToken);
             }
-            else if (packet is MqttPublishPacket publishPacket)
+
+            if (packet is MqttPubRelPacket pubRelPacket)
             {
-                await HandleIncomingPublishPacketAsync(adapter, publishPacket, cancellationToken);
+                return HandleIncomingPubRelPacketAsync(adapter, pubRelPacket, cancellationToken);
             }
-            else if (packet is MqttPubRelPacket pubRelPacket)
+
+            if (packet is MqttPubRecPacket pubRecPacket)
             {
-                await HandleIncomingPubRelPacketAsync(adapter, pubRelPacket, cancellationToken);
+                return adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, pubRecPacket.CreateResponse<MqttPubRelPacket>());
             }
-            else if (packet is MqttPubRecPacket pubRecPacket)
+
+            if (packet is MqttPubAckPacket || packet is MqttPubCompPacket)
             {
-                await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, pubRecPacket.CreateResponse<MqttPubRelPacket>());
+                // Discard message.
+                return Task.FromResult(0);
             }
-            else if (packet is MqttPubAckPacket || packet is MqttPubCompPacket)
+
+            if (packet is MqttSubscribePacket subscribePacket)
             {
-                // Discard message.
+                return HandleIncomingSubscribePacketAsync(adapter, subscribePacket, cancellationToken);
             }
-            else if (packet is MqttPingReqPacket)
+
+            if (packet is MqttUnsubscribePacket unsubscribePacket)
             {
-                await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttPingRespPacket());
+                return adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, _subscriptionsManager.Unsubscribe(unsubscribePacket));
             }
-            else if (packet is MqttDisconnectPacket || packet is MqttConnectPacket)
+            
+            if (packet is MqttDisconnectPacket || packet is MqttConnectPacket)
             {
                 Stop();
+                return Task.FromResult(0);
             }
-            else
+
+            _logger.LogWarning("Client '{0}': Received not supported packet ({1}). Closing connection.", ClientId, packet);
+            Stop();
+
+            return Task.FromResult(0);
+        }
+
+        private async Task HandleIncomingSubscribePacketAsync(IMqttCommunicationAdapter adapter, MqttSubscribePacket subscribePacket, CancellationToken cancellationToken)
+        {
+            var subscribeResult = _subscriptionsManager.Subscribe(subscribePacket, ClientId);
+            await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, subscribeResult.ResponsePacket);
+            EnqueueRetainedMessages(subscribePacket);
+
+            if (subscribeResult.CloseConnection)
             {
-                _logger.LogWarning("Client '{0}': Received not supported packet ({1}). Closing connection.", ClientId, packet);
+                await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttDisconnectPacket());
                 Stop();
             }
         }
diff --git a/MQTTnet.Core/Server/MqttClientSessionsManager.cs b/MQTTnet.Core/Server/MqttClientSessionsManager.cs
index 0e92867..62cc1d8 100644
--- a/MQTTnet.Core/Server/MqttClientSessionsManager.cs
+++ b/MQTTnet.Core/Server/MqttClientSessionsManager.cs
@@ -39,12 +39,12 @@ namespace MQTTnet.Core.Server
 
         public MqttClientRetainedMessagesManager RetainedMessagesManager { get; }
 
-        public async Task RunClientSessionAsync(IMqttCommunicationAdapter clientAdapter)
+        public async Task RunClientSessionAsync(IMqttCommunicationAdapter clientAdapter, CancellationToken cancellationToken)
         {
             var clientId = string.Empty;
             try
             {
-                if (!(await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false) is MqttConnectPacket connectPacket))
+                if (!(await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false) is MqttConnectPacket connectPacket))
                 {
                     throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
                 }
@@ -57,7 +57,7 @@ namespace MQTTnet.Core.Server
                 var connectReturnCode = ValidateConnection(connectPacket);
                 if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
                 {
-                    await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
+                    await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttConnAckPacket
                     {
                         ConnectReturnCode = connectReturnCode
                     }).ConfigureAwait(false);
@@ -67,7 +67,7 @@ namespace MQTTnet.Core.Server
 
                 var clientSession = GetOrCreateClientSession(connectPacket);
 
-                await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
+                await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttConnAckPacket
                 {
                     ConnectReturnCode = connectReturnCode,
                     IsSessionPresent = clientSession.IsExistingSession
diff --git a/MQTTnet.Core/Server/MqttClientSubscriptionsManager.cs b/MQTTnet.Core/Server/MqttClientSubscriptionsManager.cs
index 7808276..1b0d6c4 100644
--- a/MQTTnet.Core/Server/MqttClientSubscriptionsManager.cs
+++ b/MQTTnet.Core/Server/MqttClientSubscriptionsManager.cs
@@ -16,7 +16,7 @@ namespace MQTTnet.Core.Server
             _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
         }
 
-        public MqttClientSubscribeResult Subscribe(MqttSubscribePacket subscribePacket)
+        public MqttClientSubscribeResult Subscribe(MqttSubscribePacket subscribePacket, string clientId)
         {
             if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
 
@@ -27,7 +27,7 @@ namespace MQTTnet.Core.Server
             {
                 foreach (var topicFilter in subscribePacket.TopicFilters)
                 {
-                    var interceptorContext = new MqttSubscriptionInterceptorContext("", topicFilter);
+                    var interceptorContext = new MqttSubscriptionInterceptorContext(clientId, topicFilter);
                     _options.SubscriptionsInterceptor?.Invoke(interceptorContext);
                     responsePacket.SubscribeReturnCodes.Add(interceptorContext.AcceptSubscription ? MqttSubscribeReturnCode.SuccessMaximumQoS1 : MqttSubscribeReturnCode.Failure);
                     
diff --git a/MQTTnet.Core/Server/MqttServer.cs b/MQTTnet.Core/Server/MqttServer.cs
index 8f3800c..f1ed791 100644
--- a/MQTTnet.Core/Server/MqttServer.cs
+++ b/MQTTnet.Core/Server/MqttServer.cs
@@ -109,7 +109,7 @@ namespace MQTTnet.Core.Server
 
         private void OnClientAccepted(object sender, MqttServerAdapterClientAcceptedEventArgs eventArgs)
         {
-            eventArgs.SessionTask = Task.Run(async () => await _clientSessionsManager.RunClientSessionAsync(eventArgs.Client), _cancellationTokenSource.Token);
+            eventArgs.SessionTask = Task.Run(async () => await _clientSessionsManager.RunClientSessionAsync(eventArgs.Client, _cancellationTokenSource.Token), _cancellationTokenSource.Token);
         }
 
         private void OnClientConnected(object sender, MqttClientConnectedEventArgs eventArgs)