The underlying connection was closed: An unexpected error occurred on a receive FTP
===

I want to download file from the ftp server.
I have written following code to download file from ftp

 public void downloadFile(string FTPAddress, string filename, string username, string    password, string destFile)
        {
            try
            {
                FtpWebRequest request = FtpWebRequest.Create(FTPAddress + filename) as FtpWebRequest;
                request.Method = WebRequestMethods.Ftp.DownloadFile;
                request.Credentials = new NetworkCredential(username, password);
                request.UsePassive = true;
                request.UseBinary = true;
                request.UseBinary = true;
                request.KeepAlive = false; //close the connection when done
                request.Timeout = 60000;
                //Streams
                using (var response = request.GetResponse())
                {
                    
                    using (Stream reader = response.GetResponseStream())
                    {
                        byte[] buffer = new byte[1024];
                        using (Stream streamFile = File.Create(destFile))
                        {
                            while (true)
                            {
                                int bytesRead = reader.Read(buffer, 0, buffer.Length);
                                if (bytesRead == 0)
                                {
                                    break;
                                }
                                else
                                {
                                    streamFile.Write(buffer, 0, bytesRead);
                                 
                                }
                            }
                        }
                    }
                }
            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);             
            }
        }       


But when running this code giving me exception : The underlying connection was closed: An unexpected error occurred on a receive. 


What can be problem help me...