diff --git a/TLSharp.Core/Network/MtProtoSender.cs b/TLSharp.Core/Network/MtProtoSender.cs
index f7d9dc9..98dd95c 100644
--- a/TLSharp.Core/Network/MtProtoSender.cs
+++ b/TLSharp.Core/Network/MtProtoSender.cs
@@ -18,6 +18,8 @@ namespace TLSharp.Core.Network
     {
         //private ulong sessionId = GenerateRandomUlong();
 
+        private static NLog.Logger logger = NLog.LogManager.GetLogger("MTProto");
+
         private readonly uint UpdatesTooLongID = (uint) new TeleSharp.TL.TLUpdatesTooLong ().Constructor;
 
         private TcpTransport _transport;
@@ -88,7 +90,9 @@ namespace TLSharp.Core.Network
                     plaintextWriter.Write(packet.Length);
                     plaintextWriter.Write(packet);
 
-                    msgKey = Helpers.CalcMsgKey(plaintextPacket.GetBuffer());
+                    var buffer = plaintextPacket.GetBuffer();
+                    logger.Debug(Sniffer.MessageOut(buffer));
+                    msgKey = Helpers.CalcMsgKey(buffer);
                     ciphertext = AES.EncryptAES(Helpers.CalcKey(_session.AuthKey.Data, msgKey, true), plaintextPacket.GetBuffer());
                 }
             }
@@ -123,6 +127,7 @@ namespace TLSharp.Core.Network
                 AESKeyData keyData = Helpers.CalcKey(_session.AuthKey.Data, msgKey, false);
 
                 byte[] plaintext = AES.DecryptAES(keyData, inputReader.ReadBytes((int)(inputStream.Length - inputStream.Position)));
+                logger.Debug(Sniffer.MessageIn(plaintext));
 
                 using (MemoryStream plaintextStream = new MemoryStream(plaintext))
                 using (BinaryReader plaintextReader = new BinaryReader(plaintextStream))
diff --git a/TLSharp.Core/Network/Sniffer.cs b/TLSharp.Core/Network/Sniffer.cs
new file mode 100644
index 0000000..e80a105
--- /dev/null
+++ b/TLSharp.Core/Network/Sniffer.cs
@@ -0,0 +1,25 @@
+using System;
+using System.Text;
+
+namespace TLSharp.Core.Network
+{
+    public static class Sniffer
+    {
+        public static string MessageOut(byte[] data)
+        {
+            return WriteMessage(new StringBuilder("[OUT]:"), data);
+        }
+
+        public static string MessageIn(byte[] data)
+        {
+            return WriteMessage(new StringBuilder("[IN]:"), data);
+        }
+
+        private static string WriteMessage(StringBuilder log, byte[] data)
+        {
+            foreach (var b in data)
+                log.AppendFormat(" {:x2}", b);
+            return log.ToString();
+        }
+    }
+}
diff --git a/TLSharp.Core/TLSharp.Core.csproj b/TLSharp.Core/TLSharp.Core.csproj
index fbef942..7cca179 100644
--- a/TLSharp.Core/TLSharp.Core.csproj
+++ b/TLSharp.Core/TLSharp.Core.csproj
@@ -42,6 +42,9 @@
     <Reference Include="System.Data" />
     <Reference Include="System.Net.Http" />
     <Reference Include="System.Xml" />
+    <Reference Include="NLog">
+      <HintPath>..\..\packages\NLog.4.4.12\lib\net45\NLog.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Auth\Authenticator.cs" />
@@ -68,6 +71,7 @@
     <Compile Include="Session.cs" />
     <Compile Include="TelegramClient.cs" />
     <Compile Include="Utils\Helpers.cs" />
+    <Compile Include="Network\Sniffer.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />
diff --git a/TLSharp.Core/packages.config b/TLSharp.Core/packages.config
index 204475c..518c7dc 100644
--- a/TLSharp.Core/packages.config
+++ b/TLSharp.Core/packages.config
@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="MarkerMetro.Unity.Ionic.Zlib" version="2.0.0.14" targetFramework="net452" />
+  <package id="NLog" version="4.4.12" targetFramework="net45" />
 </packages>
\ No newline at end of file