\chapter{Heartbeat}
\label{chap:heartbeat}

repeat introduction of heartbeat from chap:background, figure with focus on gameserver-masterserver interaction.

\begin{figure}[h]
  \centering
  \includegraphics[width=\textwidth]{img/overview-hb}
  \caption{Focus on interaction between gameserver and masterserver}\label{fig:overviewhb}
\end{figure}

explanation of purpose, UDP information which it contains and/or is meant to convey.
\\
security challenge (secure/validate)
\\
ports that are opened, listening\\
\\

\begin{figure}[H]
  \centering
  \includegraphics[width=\textwidth]{img/uplink-exchange}
  \caption{Interaction between gameserver and masterserver}\label{fig:uplink}
\end{figure}