How to use NegotiateStream with Tcpclient ?

TcpClient tcpclient = new TcpClient();
            try
            {
                tcpclient.Connect("192.168.1.1", 23);
                NetworkStream ns = tcpclient.GetStream();
 
 
                byte[] inStream = new byte[10025];
                ns.Read(inStream, 0, (int)tcpclient.ReceiveBufferSize);
                string returndata = System.Text.Encoding.ASCII.GetString(inStream);
                Console.WriteLine("Data from Server : " + returndata);
                //string password = "admin";
                
 
                
                byte[] msg = Encoding.ASCII.GetBytes("admin");
                ns.Write(msg, 0, msg.Length);
                ns.Flush();
 
                
            }
            catch
            {
                
            }