Uploading large files

public static void Upload(string filename)
        {
            FtpWebRequest request = FtpWebRequest)FtpWebRequest.Create("ftp://64.565.210.41" + "/" +
            Path.GetFileName(@filename));
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential("Username", "password");
            request.UsePassive = true;
            request.UseBinary = true;
            request.KeepAlive = false;
            FileStream stream = File.OpenRead(@filename);
            byte[] buffer = new byte[stream.Length];
            stream.Read(buffer, 0, buffer.Length);
            stream.Close();
            Stream reqStream = request.GetRequestStream();
            reqStream.Write(buffer, 0, buffer.Length);
            reqStream.Close();
        }