# [or-cvs] r19090: {projects} Correct typo, scale down figures a bit. (projects/performance)

kloesing at seul.org kloesing at seul.org
Fri Mar 20 19:15:50 UTC 2009

Author: kloesing
Date: 2009-03-20 15:15:50 -0400 (Fri, 20 Mar 2009)
New Revision: 19090

Modified:
projects/performance/performance.tex
Log:
Correct typo, scale down figures a bit.

Modified: projects/performance/performance.tex
===================================================================
--- projects/performance/performance.tex	2009-03-20 07:28:07 UTC (rev 19089)
+++ projects/performance/performance.tex	2009-03-20 19:15:50 UTC (rev 19090)
@@ -919,14 +919,16 @@
However, as load drops, the optimized selection algorithm favors slow
relays less and faster relays more; many relays are not used at all.

-\begin{figure}
-\includegraphics[width=\textwidth]{node-selection/optimum-selection-probabilities}
+\begin{figure}[t]
+\centering
+\includegraphics[width=0.6\textwidth]{node-selection/optimum-selection-probabilities}
\caption{Optimum relay selection probabilities for a variety of network loads. Tor is currently at around 50\% utilization. The relay selection probabilities currently used by Tor are shown in black.}
\label{fig:optimum-selection}
\end{figure}

-\begin{figure}
-\includegraphics[width=\textwidth]{node-selection/relative-selection-probabilities}
+\begin{figure}[t]
+\centering
+\includegraphics[width=0.6\textwidth]{node-selection/relative-selection-probabilities}
\caption{Difference between Tor's current relay selection probabilities and the optimum, for a variety of network loads. For Tor's current network load ($\approx 50$\%) shown in pink, the slowest relays are not used at all, and the slower relays are favoured less.}
\label{fig:relative-selection}
\end{figure}
@@ -956,8 +958,9 @@
practice than the one we had in mind when we tuned our selection biases,
then we end up overbalancing the network in the other direction.

-\begin{figure}
+\begin{figure}[t]
+\centering
\caption{Average network latency against network load. Three relay selection probabilities are shown, optimized for 50\%, 75\%, and 90\% network load. The Tor relay selection algorithm is also included (black). The dots on the $x$ axis show the level of network load at which the relay selection probability distributions are optimized for. The line is cut off when the model predicts that at least one relay will have an infinite queue length, which occurs before load $=$ capacity for all relay selection algorithms except for Tor's current one.}
\end{figure}
@@ -1109,7 +1112,7 @@
For example, an attacker who wishes to monitor traffic could create
several relays, on distinct /16 subnets, but with low latency between them.
A Tor client trying to minimize latency would be more likely to select
-these relays for both entry than exit than it would otherwise.
+these relays for both entry and exit than it would otherwise.
This particular problem could be mitigated by selecting entry and
exit relay as normal, and only using latency measurements to select the
middle relay.
@@ -1142,8 +1145,9 @@
candidates for more circuits, and hence will be more heavily loaded
compared to relays with restrictive policies.

-\begin{figure}
-\includegraphics[width=\textwidth]{node-selection/exit-capacity}
+\begin{figure}[t]
+\centering
+\includegraphics[width=0.6\textwidth]{node-selection/exit-capacity}
\caption{Exit relay capacity, in terms of number of relays and advertised
bandwidth for a selection of port numbers.}
\label{fig:exit-capacity}
@@ -1283,8 +1287,9 @@
extension times (how long it takes to establish each hop of a circuit);
the bumps are easily seen in \prettyref{fig:extension-times}.

-\begin{figure}
-\includegraphics[width=\textwidth]{extensiontimes}
+\begin{figure}[t]
+\centering
+\includegraphics[width=0.6\textwidth]{extensiontimes}
\caption{Number of seconds it takes to establish each hop of a 3-hop
circuit. The higher density of samples around 2s, 3s, etc indicate that
rate limiting at each relay is introducing extra delay into the
@@ -1582,8 +1587,9 @@
observed by Andreas Pfitzmann in response to a presentation at the PET
Symposium~\cite{wendolsky-pet2007}.}

-\begin{figure}
-\includegraphics{equilibrium}
+\begin{figure}[t]
+\centering
+\includegraphics[width=0.6\textwidth]{equilibrium}
\caption{Hypothetical supply and demand curves for Tor network
resources. As supply goes up, point A corresponds to no increase in users,
whereas points B and C represent more users arriving to use up some of