diff --git a/ZeroLevel/Services/Network/FileTransfer/FileReader.cs b/ZeroLevel/Services/Network/FileTransfer/FileReader.cs
index d275fbc..128dbb2 100644
--- a/ZeroLevel/Services/Network/FileTransfer/FileReader.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/FileReader.cs
@@ -33,7 +33,7 @@ namespace ZeroLevel.Services.Network.FileTransfer
                 {
                     var fragment = new FileFrame
                     {
-                        UploadTaskId = _startInfo.FileUploadTaskId,
+                        UploadFileTaskId = _startInfo.UploadFileTaskId,
                         Offset = offset * CHUNK_SIZE,
                         Payload = new byte[bytesRead]
                     };
@@ -47,7 +47,7 @@ namespace ZeroLevel.Services.Network.FileTransfer
 
         public FileEndFrame GetCompleteInfo()
         {
-            return new FileEndFrame { FileUploadTaskId = _startInfo.FileUploadTaskId };
+            return new FileEndFrame { UploadFileTaskId = _startInfo.UploadFileTaskId };
         }
     }
 }
diff --git a/ZeroLevel/Services/Network/FileTransfer/FileReceiver.cs b/ZeroLevel/Services/Network/FileTransfer/FileReceiver.cs
index c9a13d3..f707247 100644
--- a/ZeroLevel/Services/Network/FileTransfer/FileReceiver.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/FileReceiver.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using ZeroLevel.Models;
 using ZeroLevel.Services.Network.FileTransfer.Model;
 
 namespace ZeroLevel.Services.Network.FileTransfer
@@ -40,10 +41,12 @@ namespace ZeroLevel.Services.Network.FileTransfer
         private string _basePath;
         private string _disk_prefix;
 
-        private readonly Dictionary<int, FileWriter> _incoming = new Dictionary<int, FileWriter>();
+        private readonly Dictionary<long, FileWriter> _incoming = new Dictionary<long, FileWriter>();
         private readonly object _locker = new object();
         private long _cleanErrorsTaskId;
 
+        private readonly Dictionary<long, object> _incomingLocks = new Dictionary<long, object>();
+
         public FileReceiver(string path, string disk_prefix = "DRIVE_")
         {
             _disk_prefix = disk_prefix;
@@ -68,37 +71,65 @@ namespace ZeroLevel.Services.Network.FileTransfer
 
         public void Incoming(FileStartFrame info, string clientFolderName)
         {
-            if (false == _incoming.ContainsKey(info.FileUploadTaskId))
+            try
             {
-                lock (_locker)
+                if (false == _incoming.ContainsKey(info.UploadFileTaskId))
                 {
-                    if (false == _incoming.ContainsKey(info.FileUploadTaskId))
+                    lock (_locker)
                     {
-                        string path = BuildFilePath(clientFolderName, info.FilePath);
-                        _incoming.Add(info.FileUploadTaskId, new FileWriter(path));
+                        if (false == _incoming.ContainsKey(info.UploadFileTaskId))
+                        {
+                            _incomingLocks.Add(info.UploadFileTaskId, new object());
+                            lock (_incomingLocks[info.UploadFileTaskId])
+                            {
+                                string path = BuildFilePath(clientFolderName, info.FilePath);
+                                _incoming.Add(info.UploadFileTaskId, new FileWriter(path));
+                            }
+                        }
                     }
                 }
             }
+            catch (Exception ex)
+            {
+                Log.Error("[FileReceiver]", ex);
+            }
         }
 
         public void Incoming(FileFrame chunk)
         {
-            FileWriter stream;
-            if (_incoming.TryGetValue(chunk.UploadTaskId, out stream))
+            try
             {
-                stream.Write(chunk.Offset, chunk.Payload);
+                FileWriter stream;
+                if (_incoming.TryGetValue(chunk.UploadFileTaskId, out stream))
+                {
+                    lock (_incomingLocks[chunk.UploadFileTaskId])
+                    {
+                        stream.Write(chunk.Offset, chunk.Payload);
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                Log.Error("[FileReceiver]", ex);
             }
         }
 
         public void Incoming(FileEndFrame info)
         {
-            lock (_locker)
+            try
+            {
+                lock (_locker)
+                {
+                    Remove(info.UploadFileTaskId);
+                }
+            }
+            catch (Exception ex)
             {
-                Remove(info.FileUploadTaskId);
+                Log.Error("[FileReceiver]", ex);
             }
         }
 
-        private void Remove(int uploadTaskId)
+        private void Remove(long uploadTaskId)
         {
             FileWriter stream;
             if (_incoming.TryGetValue(uploadTaskId, out stream))
diff --git a/ZeroLevel/Services/Network/FileTransfer/FileServer.cs b/ZeroLevel/Services/Network/FileTransfer/FileServer.cs
index bf6a56a..0494359 100644
--- a/ZeroLevel/Services/Network/FileTransfer/FileServer.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/FileServer.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using ZeroLevel.Models;
 using ZeroLevel.Network;
 using ZeroLevel.Services.Network.FileTransfer.Model;
 
diff --git a/ZeroLevel/Services/Network/FileTransfer/Model/FileEndFrame.cs b/ZeroLevel/Services/Network/FileTransfer/Model/FileEndFrame.cs
index e6ef3e9..a6a7cda 100644
--- a/ZeroLevel/Services/Network/FileTransfer/Model/FileEndFrame.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/Model/FileEndFrame.cs
@@ -3,18 +3,19 @@
 namespace ZeroLevel.Services.Network.FileTransfer.Model
 {
     public sealed class FileEndFrame
-        : IBinarySerializable
+        : IBinarySerializable, IFileTransferInfo
     {
-        public int FileUploadTaskId;
+        public FileTransferInfoType TransferInfoType => FileTransferInfoType.End;
+        public long UploadFileTaskId { get; set; }
 
         public void Serialize(IBinaryWriter writer)
         {
-            writer.WriteInt32(this.FileUploadTaskId);
+            writer.WriteLong(this.UploadFileTaskId);
         }
 
         public void Deserialize(IBinaryReader reader)
         {
-            this.FileUploadTaskId = reader.ReadInt32();
+            this.UploadFileTaskId = reader.ReadLong();
         }
     }
 }
diff --git a/ZeroLevel/Services/Network/FileTransfer/Model/FileFrame.cs b/ZeroLevel/Services/Network/FileTransfer/Model/FileFrame.cs
index 2eb52dd..71be19d 100644
--- a/ZeroLevel/Services/Network/FileTransfer/Model/FileFrame.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/Model/FileFrame.cs
@@ -3,22 +3,24 @@
 namespace ZeroLevel.Services.Network.FileTransfer.Model
 {
     public sealed class FileFrame :
-        IBinarySerializable
+        IBinarySerializable, IFileTransferInfo
     {
-        public int UploadTaskId { get; set; }
+        public FileTransferInfoType TransferInfoType => FileTransferInfoType.Frame;
+
+        public long UploadFileTaskId { get; set; }
         public long Offset { get; set; }
         public byte[] Payload { get; set; }
 
         public void Serialize(IBinaryWriter writer)
         {
-            writer.WriteInt32(this.UploadTaskId);
+            writer.WriteLong(this.UploadFileTaskId);
             writer.WriteLong(this.Offset);
             writer.WriteBytes(this.Payload);
         }
 
         public void Deserialize(IBinaryReader reader)
         {
-            this.UploadTaskId = reader.ReadInt32();
+            this.UploadFileTaskId = reader.ReadLong();
             this.Offset = reader.ReadLong();
             this.Payload = reader.ReadBytes();
         }
diff --git a/ZeroLevel/Services/Network/FileTransfer/Model/FileStartFrame.cs b/ZeroLevel/Services/Network/FileTransfer/Model/FileStartFrame.cs
index 957d65f..ba16844 100644
--- a/ZeroLevel/Services/Network/FileTransfer/Model/FileStartFrame.cs
+++ b/ZeroLevel/Services/Network/FileTransfer/Model/FileStartFrame.cs
@@ -4,24 +4,26 @@ using ZeroLevel.Services.Serialization;
 namespace ZeroLevel.Services.Network.FileTransfer.Model
 {
     public sealed class FileStartFrame
-        : IBinarySerializable
+        : IBinarySerializable, IFileTransferInfo
     {
-        private static int _uploadTaskIdCounter = 0;
+        private static long _uploadTaskIdCounter = 0;
 
-        public int FileUploadTaskId;
+        public FileTransferInfoType TransferInfoType => FileTransferInfoType.Start;
+
+        public long UploadFileTaskId { get; set; }
         public string FilePath;
         public long Size;
 
         public void Serialize(IBinaryWriter writer)
         {
-            writer.WriteInt32(this.FileUploadTaskId);
+            writer.WriteLong(this.UploadFileTaskId);
             writer.WriteString(this.FilePath);
             writer.WriteLong(this.Size);
         }
 
         public void Deserialize(IBinaryReader reader)
         {
-            this.FileUploadTaskId = reader.ReadInt32();
+            this.UploadFileTaskId = reader.ReadLong();
             this.FilePath = reader.ReadString();
             this.Size = reader.ReadLong();
         }
@@ -32,7 +34,7 @@ namespace ZeroLevel.Services.Network.FileTransfer.Model
             return new FileStartFrame
             {
                 FilePath = fi.FullName,
-                FileUploadTaskId = Interlocked.Increment(ref _uploadTaskIdCounter),
+                UploadFileTaskId = Interlocked.Increment(ref _uploadTaskIdCounter),
                 Size = fi.Length
             };
         }
diff --git a/ZeroLevel/Services/Network/FileTransfer/Model/IFileTransferInfo.cs b/ZeroLevel/Services/Network/FileTransfer/Model/IFileTransferInfo.cs
new file mode 100644
index 0000000..c80da97
--- /dev/null
+++ b/ZeroLevel/Services/Network/FileTransfer/Model/IFileTransferInfo.cs
@@ -0,0 +1,15 @@
+namespace ZeroLevel.Services.Network.FileTransfer.Model
+{
+    public enum FileTransferInfoType
+    {
+        Start,
+        Frame,
+        End
+    }
+
+    public interface IFileTransferInfo
+    {
+        long UploadFileTaskId { get; }
+        FileTransferInfoType TransferInfoType { get; }
+    }
+}