improved margings for creating a bounded version of the master thesis

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2026-02-24 17:08:42 +01:00
parent 170461431b
commit f1049f51f2
4 changed files with 260 additions and 262 deletions

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@@ -2,6 +2,250 @@
\label{Introduction} \label{Introduction}
This chapter introduces the Clan project, articulates its fundamental \subsection{Motivation}
objectives, outlines the key components, and examines the driving
factors motivating its development. Peer-to-peer architectures promise censorship-resistant, fault-tolerant
infrastructure by eliminating single points of failure
\cite{shukla_towards_2021}.
These architectures underpin a growing range of systems---from IoT
edge computing
and content delivery networks to blockchain platforms like Ethereum.
Yet realizing these benefits requires distributing nodes across
genuinely diverse hosting entities.
In practice, this diversity remains illusory.
Amazon, Hetzner, and OVH collectively host 70\% of all Ethereum nodes
(see Figure~\ref{fig:ethernodes_hosting}),
concentrating nominally decentralized infrastructure
within a handful of cloud providers.
More concerning, these providers operate under overlapping regulatory
jurisdictions,
predominantly the United States and the European Union.
This concentration undermines technical sovereignty:
a single governmental action could compel service termination,
data disclosure, or traffic manipulation across a majority of the network.
\begin{figure}[H]
\centering
\includegraphics[width=1\textwidth]{Figures/ethernodes_hosting.png}
\caption{Distribution of Ethereum nodes hosted by various providers
\cite{noauthor_isps_nodate}}
\label{fig:ethernodes_hosting}
\end{figure}
Why does this centralization persist despite the explicit goals of
decentralization?
The answer lies in the practical barriers to self-hosting.
Cloud providers offer static IP addresses and publicly routable endpoints,
eliminating the networking complexity that plagues residential and
small-office deployments.
Most internet-connected devices sit behind Network Address Translation (NAT),
which prevents incoming connections without explicit port forwarding
or relay infrastructure.
Combined with dynamic IP assignments from ISPs, maintaining stable
peer connectivity
from self-hosted infrastructure traditionally required significant
technical expertise.
Overlay VPNs offer a solution to this fundamental barrier.
By establishing encrypted tunnels that traverse NAT boundaries,
mesh VPNs enable direct peer-to-peer connectivity without requiring
static IP addresses or manual firewall configuration.
Each node receives a stable virtual address within the overlay network,
regardless of its underlying network topology.
This capability is transformative:
it allows a device behind consumer-grade NAT to participate
as a first-class peer in a distributed system,
removing the primary technical advantage that cloud providers hold.
The Clan deployment framework builds on this foundation.
Clan leverages Nix and NixOS to eliminate entire classes of
configuration errors prevalent in contemporary infrastructure deployment,
reducing operational overhead to a degree where a single administrator
can reliably self-host complex distributed services.
Overlay VPNs are central to Clan's architecture,
providing the secure peer connectivity that enables nodes
to form cohesive networks regardless of their physical location or
NAT situation.
As illustrated in Figure~\ref{fig:vision-stages}, Clan envisions
a web interface that enables users to design and deploy private P2P networks
with minimal configuration, assisted by an integrated LLM
for contextual guidance and troubleshooting.
During the development of Clan, a recurring challenge became apparent:
practitioners held divergent preferences for mesh VPN solutions,
each citing different edge cases where their chosen VPN
proved unreliable or lacked essential features.
These discussions were largely grounded in anecdotal evidence
rather than systematic evaluation.
This observation revealed a clear need for rigorous,
evidence-based comparison of peer-to-peer overlay VPN implementations.
Existing research on this topic remains sparse.
One notable work from 2024, ``Full-mesh VPN performance evaluation
for a secure edge-cloud continuum'' \cite{kjorveziroski_full-mesh_2024},
benchmarks a subset of mesh VPNs but focuses primarily
on solutions with a central point of failure.
In contrast, this thesis evaluates more widely adopted mesh VPNs
with an emphasis on fully decentralized architectures.
Furthermore, that study relied exclusively on iperf3 for performance
measurement,
whereas our benchmark suite includes real-world workloads
to better reflect practical usage patterns.
A further motivation was to create a fully automated benchmarking framework
capable of generating a public leaderboard,
similar in spirit to the js-framework-benchmark
(see Figure~\ref{fig:js-framework-benchmark}).
By providing an accessible web interface with regularly updated results,
we hope to encourage P2P VPN developers to optimize their implementations
in pursuit of top rankings.
\begin{figure}[H]
\centering
\includegraphics[width=1\textwidth]{Figures/krause-js-framework.png}
\caption{js-framework-benchmark results for Chrome 144.0
\cite{krause_krausestjs-framework-benchmark_2026}}
\label{fig:js-framework-benchmark}
\end{figure}
\begin{figure}[h]
\centering
% Row 1
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage1.png}
\caption{Stage 1}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage2.png}
\caption{Stage 2}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 2
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage3.png}
\caption{Stage 3}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage4.png}
\caption{Stage 4}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 3
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage5.png}
\caption{Stage 5}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage6.png}
\caption{Stage 6}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 4
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage7.png}
\caption{Stage 7}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage8.png}
\caption{Stage 8}
\end{subfigure}
\caption{Visionary Webinterface to Setup a Clan Family Network}
\label{fig:vision-stages}
\end{figure}
\subsection{Research Contribution}
TODO
\subsection{Related Work}
\subsubsection{Nix: A Safe and Policy-Free System for Software Deployment}
Nix addresses significant issues in software deployment by utilizing
cryptographic hashes to ensure unique paths for component instances
\cite{dolstra_nix_2004}. Features such as concurrent installation of
multiple versions, atomic upgrades, and safe garbage collection make
Nix a flexible deployment system. This work uses Nix to ensure that
all VPN builds and system configurations are deterministic.
\subsubsection{NixOS: A Purely Functional Linux Distribution}
NixOS extends Nix principles to Linux system configuration
\cite{dolstra_nixos_2008}. System configurations are reproducible and
isolated from stateful interactions typical in imperative package
management. This property is essential for ensuring identical test
environments across benchmark runs.
\subsubsection{A Comparative Study on Virtual Private Networks}
Lackorzynski et al.\ \cite{lackorzynski_comparative_2019} evaluate
VPN protocols in the context of industrial communication systems (Industry 4.0),
benchmarking OpenVPN, IPSec, Tinc, Freelan, MACsec, and WireGuard.
Their analysis focuses on point-to-point protocol performance; throughput,
latency, and CPU overhead; rather than overlay network behavior.
In contrast, this thesis evaluates VPNs that provide a full data plane
with peer-to-peer connectivity, NAT traversal, and dynamic peer discovery.
\subsubsection{Full-Mesh VPN Performance Evaluation}
Kjorveziroski et al.\ \cite{kjorveziroski_full-mesh_2024} provide a
comprehensive evaluation of full-mesh VPN solutions for distributed
systems. Their benchmarks analyze throughput, reliability under packet
loss, and relay behavior for VPNs including ZeroTier.
This thesis extends their work in several ways:
\begin{itemize}
\item Broader VPN selection with emphasis on fully decentralized
architectures
\item Real-world workloads (video streaming, package downloads)
beyond synthetic iperf3 tests
\item Multiple impairment profiles to characterize behavior under
varying network conditions
\item Fully reproducible experimental framework via Nix/NixOS/Clan
\end{itemize}
\subsubsection{UDP NAT and Firewall Puncturing in the Wild}
Halkes and Pouwelse~\cite{halkes_udp_2011} measure UDP hole punching
efficacy on a live P2P network using the Tribler BitTorrent client.
Their study finds that 79\% of peers are unreachable due to NAT or
firewall restrictions, yet 64\% reside behind configurations amenable
to hole punching. Among compatible peers, over 80\% of puncturing
attempts succeed, establishing hole punching as a practical NAT
traversal technique. Their timeout measurements further indicate that
keep-alive messages must be sent at least every 55 seconds to maintain
open NAT mappings.
These findings directly inform the evaluation criteria for this thesis.
All mesh VPNs tested rely on UDP hole punching for NAT traversal;
the 80\% success rate sets a baseline expectation, while the 55-second
timeout informs analysis of each implementation's keep-alive behavior
during source code review.
\subsubsection{An Overview of Packet Reordering in TCP}
TODO \cite{leung_overview_2007}
\subsubsection{Performance Evaluation of TCP over QUIC Tunnels}
TODO \cite{guo_implementation_2025}

View File

@@ -342,74 +342,3 @@ Every test result includes metadata recording:
Results are organized hierarchically by VPN, TC profile, and machine Results are organized hierarchically by VPN, TC profile, and machine
pair. Each profile directory contains a \texttt{tc\_settings.json} pair. Each profile directory contains a \texttt{tc\_settings.json}
snapshot of the exact impairment parameters applied. snapshot of the exact impairment parameters applied.
\section{Related Work}
\subsection{Nix: A Safe and Policy-Free System for Software Deployment}
Nix addresses significant issues in software deployment by utilizing
cryptographic hashes to ensure unique paths for component instances
\cite{dolstra_nix_2004}. Features such as concurrent installation of
multiple versions, atomic upgrades, and safe garbage collection make
Nix a flexible deployment system. This work uses Nix to ensure that
all VPN builds and system configurations are deterministic.
\subsection{NixOS: A Purely Functional Linux Distribution}
NixOS extends Nix principles to Linux system configuration
\cite{dolstra_nixos_2008}. System configurations are reproducible and
isolated from stateful interactions typical in imperative package
management. This property is essential for ensuring identical test
environments across benchmark runs.
\subsection{A Comparative Study on Virtual Private Networks}
Lackorzynski et al.\ \cite{lackorzynski_comparative_2019} evaluate
VPN protocols in the context of industrial communication systems (Industry 4.0),
benchmarking OpenVPN, IPSec, Tinc, Freelan, MACsec, and WireGuard.
Their analysis focuses on point-to-point protocol performance; throughput,
latency, and CPU overhead; rather than overlay network behavior.
In contrast, this thesis evaluates VPNs that provide a full data plane
with peer-to-peer connectivity, NAT traversal, and dynamic peer discovery.
\subsection{Full-Mesh VPN Performance Evaluation}
Kjorveziroski et al.\ \cite{kjorveziroski_full-mesh_2024} provide a
comprehensive evaluation of full-mesh VPN solutions for distributed
systems. Their benchmarks analyze throughput, reliability under packet
loss, and relay behavior for VPNs including ZeroTier.
This thesis extends their work in several ways:
\begin{itemize}
\item Broader VPN selection with emphasis on fully decentralized
architectures
\item Real-world workloads (video streaming, package downloads)
beyond synthetic iperf3 tests
\item Multiple impairment profiles to characterize behavior under
varying network conditions
\item Fully reproducible experimental framework via Nix/NixOS/Clan
\end{itemize}
\subsection{UDP NAT and Firewall Puncturing in the Wild}
Halkes and Pouwelse~\cite{halkes_udp_2011} measure UDP hole punching
efficacy on a live P2P network using the Tribler BitTorrent client.
Their study finds that 79\% of peers are unreachable due to NAT or
firewall restrictions, yet 64\% reside behind configurations amenable
to hole punching. Among compatible peers, over 80\% of puncturing
attempts succeed, establishing hole punching as a practical NAT
traversal technique. Their timeout measurements further indicate that
keep-alive messages must be sent at least every 55 seconds to maintain
open NAT mappings.
These findings directly inform the evaluation criteria for this thesis.
All mesh VPNs tested rely on UDP hole punching for NAT traversal;
the 80\% success rate sets a baseline expectation, while the 55-second
timeout informs analysis of each implementation's keep-alive behavior
during source code review.
\subsection{An Overview of Packet Reordering in TCP}
TODO \cite{leung_overview_2007}
\subsection{Performance Evaluation of TCP over QUIC Tunnels}
TODO \cite{guo_implementation_2025}

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@@ -1,173 +0,0 @@
\chapter{Motivation} % Main chapter title
\label{Motivation}
Peer-to-peer architectures promise censorship-resistant, fault-tolerant
infrastructure by eliminating single points of failure
\cite{shukla_towards_2021}.
These architectures underpin a growing range of systems---from IoT
edge computing
and content delivery networks to blockchain platforms like Ethereum.
Yet realizing these benefits requires distributing nodes across
genuinely diverse hosting entities.
In practice, this diversity remains illusory.
Amazon, Hetzner, and OVH collectively host 70\% of all Ethereum nodes
(see Figure~\ref{fig:ethernodes_hosting}),
concentrating nominally decentralized infrastructure
within a handful of cloud providers.
More concerning, these providers operate under overlapping regulatory
jurisdictions,
predominantly the United States and the European Union.
This concentration undermines technical sovereignty:
a single governmental action could compel service termination,
data disclosure, or traffic manipulation across a majority of the network.
\begin{figure}[H]
\centering
\includegraphics[width=1\textwidth]{Figures/ethernodes_hosting.png}
\caption{Distribution of Ethereum nodes hosted by various providers
\cite{noauthor_isps_nodate}}
\label{fig:ethernodes_hosting}
\end{figure}
Why does this centralization persist despite the explicit goals of
decentralization?
The answer lies in the practical barriers to self-hosting.
Cloud providers offer static IP addresses and publicly routable endpoints,
eliminating the networking complexity that plagues residential and
small-office deployments.
Most internet-connected devices sit behind Network Address Translation (NAT),
which prevents incoming connections without explicit port forwarding
or relay infrastructure.
Combined with dynamic IP assignments from ISPs, maintaining stable
peer connectivity
from self-hosted infrastructure traditionally required significant
technical expertise.
Overlay VPNs offer a solution to this fundamental barrier.
By establishing encrypted tunnels that traverse NAT boundaries,
mesh VPNs enable direct peer-to-peer connectivity without requiring
static IP addresses or manual firewall configuration.
Each node receives a stable virtual address within the overlay network,
regardless of its underlying network topology.
This capability is transformative:
it allows a device behind consumer-grade NAT to participate
as a first-class peer in a distributed system,
removing the primary technical advantage that cloud providers hold.
The Clan deployment framework builds on this foundation.
Clan leverages Nix and NixOS to eliminate entire classes of
configuration errors prevalent in contemporary infrastructure deployment,
reducing operational overhead to a degree where a single administrator
can reliably self-host complex distributed services.
Overlay VPNs are central to Clan's architecture,
providing the secure peer connectivity that enables nodes
to form cohesive networks regardless of their physical location or
NAT situation.
As illustrated in Figure~\ref{fig:vision-stages}, Clan envisions
a web interface that enables users to design and deploy private P2P networks
with minimal configuration, assisted by an integrated LLM
for contextual guidance and troubleshooting.
During the development of Clan, a recurring challenge became apparent:
practitioners held divergent preferences for mesh VPN solutions,
each citing different edge cases where their chosen VPN
proved unreliable or lacked essential features.
These discussions were largely grounded in anecdotal evidence
rather than systematic evaluation.
This observation revealed a clear need for rigorous,
evidence-based comparison of peer-to-peer overlay VPN implementations.
Existing research on this topic remains sparse.
One notable work from 2024, ``Full-mesh VPN performance evaluation
for a secure edge-cloud continuum'' \cite{kjorveziroski_full-mesh_2024},
benchmarks a subset of mesh VPNs but focuses primarily
on solutions with a central point of failure.
In contrast, this thesis evaluates more widely adopted mesh VPNs
with an emphasis on fully decentralized architectures.
Furthermore, that study relied exclusively on iperf3 for performance
measurement,
whereas our benchmark suite includes real-world workloads
to better reflect practical usage patterns.
A further motivation was to create a fully automated benchmarking framework
capable of generating a public leaderboard,
similar in spirit to the js-framework-benchmark
(see Figure~\ref{fig:js-framework-benchmark}).
By providing an accessible web interface with regularly updated results,
we hope to encourage P2P VPN developers to optimize their implementations
in pursuit of top rankings.
\begin{figure}[H]
\centering
\includegraphics[width=1\textwidth]{Figures/krause-js-framework.png}
\caption{js-framework-benchmark results for Chrome 144.0
\cite{krause_krausestjs-framework-benchmark_2026}}
\label{fig:js-framework-benchmark}
\end{figure}
\begin{figure}[h]
\centering
% Row 1
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage1.png}
\caption{Stage 1}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage2.png}
\caption{Stage 2}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 2
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage3.png}
\caption{Stage 3}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage4.png}
\caption{Stage 4}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 3
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage5.png}
\caption{Stage 5}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage6.png}
\caption{Stage 6}
\end{subfigure}
\vspace{1em} % Add spacing between rows
% Row 4
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage7.png}
\caption{Stage 7}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\centering
\includegraphics[width=\linewidth]{Figures/vision/stage8.png}
\caption{Stage 8}
\end{subfigure}
\caption{Visionary Webinterface to Setup a Clan Family Network}
\label{fig:vision-stages}
\end{figure}

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@@ -25,10 +25,10 @@
\documentclass[ \documentclass[
11pt, % The default document font size, options: 10pt, 11pt, 12pt 11pt, % The default document font size, options: 10pt, 11pt, 12pt
oneside, % Two side (alternating margins) for binding by default, oneside,%twoside, % Two side (alternating margins) for binding by default,
% uncomment to switch to one side % uncomment to switch to one side
english, % ngerman for German english, % ngerman for German
singlespacing, % Single line spacing, alternatives: onehalfspacing onehalfspacing, % Single line spacing, alternatives: onehalfspacing
% or doublespacing % or doublespacing
%draft, % Uncomment to enable draft mode (no pictures, no links, %draft, % Uncomment to enable draft mode (no pictures, no links,
% overfull hboxes indicated) % overfull hboxes indicated)
@@ -75,13 +75,12 @@
%---------------------------------------------------------------------------------------- %----------------------------------------------------------------------------------------
\geometry{ \geometry{
paper=a4paper, % Change to letterpaper for US letter paper=a4paper,
inner=2.5cm, % Inner margin inner=3.0cm, % Bindungsseite braucht mehr Platz
outer=3.8cm, % Outer margin outer=2.5cm, % Außenseite
bindingoffset=.5cm, % Binding offset bindingoffset=0.5cm, % Zusätzlich für Klebebindung
top=1.5cm, % Top margin top=2.5cm,
bottom=1.5cm, % Bottom margin bottom=2.0cm,
%showframe, % Uncomment to show how the type block is set on the page
} }
%---------------------------------------------------------------------------------------- %----------------------------------------------------------------------------------------
@@ -91,7 +90,7 @@
\thesistitle{Decrypting the Overlay: A Reproducible Analysis of P2P \thesistitle{Decrypting the Overlay: A Reproducible Analysis of P2P
VPN Implementation and Overhead} % Your thesis title, this is used in the title VPN Implementation and Overhead} % Your thesis title, this is used in the title
% and abstract, print it elsewhere with \ttitle % and abstract, print it elsewhere with \ttitle
\supervisor{\textsc{Ber Lorke}} % Your supervisor's name, this is %\supervisor{\textsc{Ber Lorke}} % Your supervisor's name, this is
% used in the title page, print it elsewhere with \supname % used in the title page, print it elsewhere with \supname
\examiner{Prof. Dr. \textsc{Stefan Schmid}} % Your examiner's name, \examiner{Prof. Dr. \textsc{Stefan Schmid}} % Your examiner's name,
% this is not currently used anywhere in the template, print it % this is not currently used anywhere in the template, print it
@@ -158,11 +157,11 @@ and Management}} % Your department's name and URL, this is used in
\begin{minipage}[t]{0.4\textwidth} \begin{minipage}[t]{0.4\textwidth}
\begin{flushright} \large \begin{flushright} \large
\emph{First Examiner:} \\ \emph{First Examiner:} \\
\textcolor{mdtRed}{Prof.\ Dr.\ \textsc{Stefan Schmidt}}\\[1em] \textcolor{mdtRed}{Prof.\ Dr.\ \textsc{Stefan Schmid}}\\[1em]
\emph{Second Examiner:} \\ \emph{Second Examiner:} \\
\textcolor{mdtRed}{\textsc{[TBD]}}\\[1em] \textcolor{mdtRed}{\textsc{[TBD]}}\\[1em]
\emph{Supervisor:} \\ %\emph{Supervisor:} \\
\textcolor{mdtRed}{\supname} %\textcolor{mdtRed}{\supname}
\end{flushright} \end{flushright}
\end{minipage}\\[2cm] \end{minipage}\\[2cm]
@@ -350,10 +349,9 @@ and Management}} % Your department's name and URL, this is used in
% Include the chapters of the thesis as separate files from the Chapters folder % Include the chapters of the thesis as separate files from the Chapters folder
% Uncomment the lines as you write the chapters % Uncomment the lines as you write the chapters
\include{Chapters/Motivation} \include{Chapters/Introduction}
\include{Chapters/Methodology} \include{Chapters/Methodology}
\include{Chapters/Introduction}
%\include{Chapters/Chapter1} %\include{Chapters/Chapter1}
%\include{Chapters/Chapter2} %\include{Chapters/Chapter2}