\documentclass{article}
\usepackage[usenames]{xcolor}
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\title{Servers and ports}
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\begin{tabular}{|l|l|l|}
  \hline
  \textbf{Port offset} & \textbf{Component} & \textbf{Purpose} \\
  \hline
  0 & \texttt{EncodeServer} & Listen for frame encoding requests \\
  \hline
  1 & \texttt{EncodeServer} & Listen for \texttt{DCPOMATIC\_HELLO} from masters \\
  \hline
  2 & \texttt{EncodeServerFinder} & Listen for replies to \texttt{DCPOMATIC\_HELLO} from servers \\
  \hline
  3 & Batch converter & Listen for job requests \\
  \hline
\end{tabular}


\texttt{EncodeServer} listens on \texttt{server\_port\_base}.
Receives an XML \texttt{EncodingRequest} and then the video data.
Sends back the encoded data.

\texttt{EncodeServer} also listens on $\texttt{server\_port\_base} +
1$.  A main DCP-o-matic instance broadcasts \texttt{DCPOMATIC\_HELLO}
on this port.  When a server receives this it connects to the main
DCP-o-matic on $\texttt{server\_port\_base} + 1$ and tells it what it can do.

Batch Converter listens on $\texttt{server\_port\_base} + 2$ for jobs.

\end{document}