\input{lib/preamble.tex}

\begin{document}
\begin{tikzpicture}
  \node (Device) at (4,1) [component,external] { Gerät };
  \node (WSM) at (4,9) [component,external] { WSM };
  \node (TCPConn) at (4,3.5) [component] { TCP Connector };
  \node (TLSFilter) at (4,5) [component] { TLS Filter };
  \node (WSFilter) at (4,6.5) [component] { Websocket Filter };
  \draw[very thick, rounded corners=6px] (0,2) rectangle (8,8) ++(0, 0.1) node [label, anchor=south east] { Connection Holder };
  \draw (Device) edge [<->] (TCPConn)
        (TCPConn) edge [<->] (TLSFilter)
        (TLSFilter) edge [<->] (WSFilter)
        (WSFilter) edge [<->] (WSM);
\end{tikzpicture}
\end{document}