\begin{frame}[fragile]
\frametitle{Generic Routing Encapsulation (GRE)}
\begin{itemize}
\item packet encapsulation in OSI Layer 3
\item base encapsulation protocol for PPTP
\item easy configuration
\item easy integration in existing corporate-wide Network infrastructure and NAT
\item \emph{Warning}: security rating only sufficient with EAP
\item Please see: \url{http://www.heise.de/security/artikel/Der-Todesstoss-fuer-PPTP-1701365.html}
\end{itemize}
\end{frame}