I'm writing a configuration tool for a device that can communicate via telnet. The tool sends a command via TcpClient.GetStream().Write(...), and then checks for the device response via TcpClient.GetStream().ReadByte(). This works fine in unit tests or when I'm stepping through code slowly. If I run the config tool such that it performs multiple commands consecutively, then the behavior of the read is inconsistent. By inconsistent I mean sometimes the data is missing, incomplete or partially garbled. So even though the device performed the operation and responded, my code to check for the response was unreliable. I "fixed" this problem by adding a Thread.Sleep to make sure the read method waits long enough for the device to complete its job and send back the whole response (in this case 1.5 seconds was a safe amount). I feel like this is wrong, blocking everything for a fixed time, and I wonder if there is a better way to get the read method to wait only long enough to get the whole response from the device.

private string Read()
{
    if (!tcpClient.Connected)
  throw (new Exception("Read() failed: Telnet connection not available."));
 StringBuilder sb = new StringBuilder();
 do
 {
  ParseTelnet(ref sb);
  System.Threading.Thread.Sleep(1500);
 } while (tcpClient.Available > 0);
 return sb.ToString();
}
private void ParseTelnet(ref StringBuilder sb)
{
 while (tcpClient.Available > 0)
 {
  int input = tcpClient.GetStream().ReadByte();
  switch (input)
  {
   // parse the input
   // ... do other things in special cases
   default:
    sb.Append((char)input);
    break;
  }
 }
}