%% Copyright (c) 2025 The Tor Project, inc. All rights reserved.
%% Use of this source code is governed by a BSD-style
%% license that can be found in the LICENSE file.

%% Tor network resilience
\begin{frame}{Tor network resilience - Overview}
    \textbf{What do we mean when we talk about network resilience?}
    \begin{itemize}
        \item the Tor network is not going down or getting unreliable in the face
          of potential disruptions
        \begin{itemize}
            \item when is the Tor network behaving "normal"?
            \item potential disruptions have to be detected quickly (pre-emptively)
            \item disruptions need to get mitigated early on
        \end{itemize}
        \item the Tor network is diverse
        \begin{itemize}
            \item distributed trust
            \item diverse set of relay operators
            \item diverse set of relay locations (operating systems etc.)
        \end{itemize}
    \end{itemize}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/lithuania.png}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/germany-1.png}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/germany-2.png}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/germany-3.png}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/bandwidth-growth.png}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    Exception Reporting Framework - Analysis:
    \begin{itemize}
        \item powered by "sensors" in the network doing data collection
        \item establishment of baseline metrics
        \item anomaly analysis and reporting
        \item categorization according to profiles of past incidents
    \end{itemize}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    \centering
    \includegraphics[width=0.9\textwidth]{images/p183-part1.png}

    \small\href{https://gitlab.torproject.org/tpo/network-health/team/-/milestones/2\#tab-issues}{Exception Reporting Framework milestone}
\end{frame}

\begin{frame}{Tor network resilience - Disruptions}
    Exception Reporting Framework - Mitigations:
    \begin{itemize}
        \item the network-health team sits at the center of coordinating
          the mitigations
        \item other stakeholders need to get included (network, community,
          bad-relay teams, potentially Directory Authorities)
        \item evaluation of responses and mitigation strategy
    \end{itemize}
\end{frame}


