C# - TcpClient - Detecting end of stream?

I am trying to interface an ancient network camera to my computer and I am stuck at a very fundamental problem -- detecting the end of stream.

I am using TcpClient to communicate with the camera and I can actually see it transmitting the command data, no problems here.

        List<int> incoming = new List<int>();            
        TcpClient clientSocket = new TcpClient();
        clientSocket.Connect(txtHost.Text, Int32.Parse(txtPort.Text));
        NetworkStream serverStream = clientSocket.GetStream();
        serverStream.Flush();

        byte[] command = System.Text.Encoding.ASCII.GetBytes("i640*480M");
        serverStream.Write(command, 0, command.Length);

Reading back the response is where the problem begins though. I initially thought something simple like the following bit of code would have worked:

        while (serverStream.DataAvailable)
        {
            incoming.Add(serverStream.ReadByte());
        }

But it didn't, so I had a go another version this time utilising ReadByte(). The description states:

Reads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.

so I thought I could implement something along the lines of:

        Boolean run = true;
        int rec;
        while (run)
        {
            rec = serverStream.ReadByte();

            if (rec == -1)
            {
                run = false;
                //b = (byte)'X';
            }
            else
            {
                incoming.Add(rec);
            }

        }

Nope, still doesn't work. I can actually see data coming in and after a certain point (which is not always the same, otherwise I could have simply read that many bytes every time) I start getting 0 as the value for the rest of the elements and it doesn't halt until I manually stop the execution. Here's what it looks like:

So my question is, am I missing something fundamental here? How can I detect the end of the stream?

Many thanks,

H.