We emphasize the disadvantages (not scalable)
\subsection{The new infrastructure}
+The new testing infrastructure is implemented as a client-server architecture, in which the
+Commander application start the Server application and then acts as a client requesting the Server to start BitTorrent clients.
+This system is described in figure \ref{fig:test-arch}.\\
+
+
+The Commander communicates with the Server using the following types of messages:
+
+\begin{itemize}
+ \item START - sent for starting a BitTorrent client.
+ \begin{itemize}
+\item first message contains the type, here START\_MSG
+\item second message contains a Python Dictionary data structure with the parameters
+ needed for starting the client.
+\end{itemize}
+ \item STOP - sent for stopping a running client.
+\begin{itemize}
+\item first message contains the type, here STOP\_MSG
+\item second message contains a string with the client process id.
+ \end{itemize}
+
+ \item ACK - contains $``ACK``$ and is sent by the server after receiving the message type
+ \item ACK PID - contains $''ACK <PID>''$ sent by the server after starting a client, PID is the process id.
+ \item ERROR - contains $"ERROR <error-message>``$ sent by the server when the parameters received are incorrect or the BT client can not be started.
+\end{itemize}
+We intend to extend this communication protocol with status messages sent by the Commander to check
+the BT client's progress.
+
\begin{figure}[h]
\begin{center}
\includegraphics[width = 4.5in, height = 2.2in]{img/Diagram1.png}
\end{center}
\caption{Client-Server architecture for interaction with BitTorrent clients.}
+\label{fig:test-arch}
\end{figure}
-
-
+\subsection{Commander}\label{sec:comm}
+\input{test/comm.tex}
+\subsection{Server}\label{sec:server}
\input{test/server.tex}
\ No newline at end of file
The server application resides on a virtual machine on which several BT clients are installed. It
-is started by connecting remotely using ssh, and executes as a daemon process\cite{daemon}
+is started by connecting remotely using ssh, and executes as a daemon process\cite{daemon}.
+This server is written in Python, using modules for socket communication and process handling with
+functions similar to the ones from POSIX C.
+
+
\ No newline at end of file