отправка
        FileStream Stream = File.OpenRead(strData);
        int BytesRead = -1;
        while (BytesRead != 0)
        {
        byte[] Buffer = new byte[65535];
        BytesRead = Stream.Read(Buffer, 0, 65535);

           if (localClient != null && localClient.Connected)
                localClient.GetStream().Write(Buffer, 0, Buffer.Length);
           else if (remoteClient != null && remoteClient.Connected)
                remoteClient.GetStream().Write(Buffer, 0, Buffer.Length);
         }
         Stream.Close();
                    
прием
        FileStream Writing = null;      
        if (Writing == null)
        {
              Writing = File.OpenWrite(path1 + "\\" + nam);
        }
        Writing.Write(buffer, 0, buffer.Length);
        if (buffer.Length < 65535) Writing.Close();